diff --git a/Rakefile b/Rakefile
index 560c34baa..e36ad0a3c 100644
--- a/Rakefile
+++ b/Rakefile
@@ -17,14 +17,14 @@ RSpec::Core::RakeTask.new('spec:progress') do |spec|
 end
 
 namespace :generate do
-  desc 'Generates a activedocument.yml from the template'
+  desc 'Generates an active_document.yml from the template'
   task config: :environment do
     require 'active_document'
     require 'erb'
 
-    template_path = 'lib/rails/generators/mongoid/config/templates/activedocument.yml'
+    template_path = 'lib/rails/generators/mongoid/config/templates/active_document.yml'
     config = ERB.new(File.read(template_path), trim_mode: '-').result(binding)
-    File.write('activedocument.yml', config)
+    File.write('active_document.yml', config)
   end
 end
 
diff --git a/docs/reference/configuration.txt b/docs/reference/configuration.txt
index 1d5970f71..7b2d93807 100644
--- a/docs/reference/configuration.txt
+++ b/docs/reference/configuration.txt
@@ -12,7 +12,7 @@ Configuration
    :depth: 2
    :class: singlecol
 
-ActiveDocument is customarily configured through a ``activedocument.yml`` file that specifies
+ActiveDocument is customarily configured through a ``active_document.yml`` file that specifies
 options and clients. The simplest configuration is as follows, which configures
 ActiveDocument to talk to a MongoDB server at "localhost:27017" and use the database
 named "mongoid".
@@ -43,16 +43,16 @@ configuration file for you by running the following command:
 
   rails g mongoid:config
 
-The configuration file will be placed in ``config/activedocument.yml``. An
+The configuration file will be placed in ``config/active_document.yml``. An
 initializer will also be created and placed in
 ``config/initializers/mongoid.rb``. It is recommended that all configuration
-be specified in ``config/activedocument.yml``, but if you prefer, the ``mongoid.rb``
+be specified in ``config/active_document.yml``, but if you prefer, the ``mongoid.rb``
 initializer may also be used to set configuration options. Note, though, that
-settings in ``activedocument.yml`` always take precedence over settings in the
+settings in ``active_document.yml`` always take precedence over settings in the
 initializer.
 
 If you are not using Ruby on Rails, you can copy the minimal configuration
-given above and save it as ``config/activedocument.yml``.
+given above and save it as ``config/active_document.yml``.
 
 
 Loading ActiveDocument Configuration
@@ -78,10 +78,10 @@ the configuration file path as its argument, as follows:
 .. code-block:: ruby
 
   # Use automatically detected environment name
-  ActiveDocument.load!('path/to/your/activedocument.yml')
+  ActiveDocument.load!('path/to/your/active_document.yml')
 
   # Specify environment name manually
-  ActiveDocument.load!('path/to/your/activedocument.yml', :production)
+  ActiveDocument.load!('path/to/your/active_document.yml', :production)
 
 When ActiveDocument is asked to automatically detect the environment name,
 it does so by examining the following sources, in order:
@@ -119,7 +119,7 @@ current environment - but it does support defining multiple clients.
 ActiveDocument Configuration Options
 =============================
 
-The following annotated example ``activedocument.yml`` demonstrates how ActiveDocument
+The following annotated example ``active_document.yml`` demonstrates how ActiveDocument
 can be configured.
 
 ActiveDocument delegates to the Ruby driver for client configuration. Please review
@@ -793,7 +793,7 @@ the Ruby driver, which implements the three algorithms that are supported by Mon
   requires the `zstd-ruby <https://rubygems.org/gems/zstd-ruby>`_ library to
   be installed.
 
-To use wire protocol compression, configure the Ruby driver options within ``activedocument.yml``:
+To use wire protocol compression, configure the Ruby driver options within ``active_document.yml``:
 
 .. code-block:: yaml
 
diff --git a/docs/reference/persistence-configuration.txt b/docs/reference/persistence-configuration.txt
index f49868d3d..fe76a4d1d 100644
--- a/docs/reference/persistence-configuration.txt
+++ b/docs/reference/persistence-configuration.txt
@@ -115,7 +115,7 @@ database, or a different client. The following example would store the Band clas
 default into a collection named "artists" in the database named "music", with the client "analytics".
 
 Note that the value supplied to the ``client`` option must be configured under ``clients``
-in your activedocument.yml.
+in your active_document.yml.
 
 .. code-block:: ruby
 
diff --git a/docs/reference/rails-integration.txt b/docs/reference/rails-integration.txt
index 266a9c998..7162c7cf4 100644
--- a/docs/reference/rails-integration.txt
+++ b/docs/reference/rails-integration.txt
@@ -23,9 +23,9 @@ You can set ActiveDocument configuration options in your ``application.rb`` alon
 other Rails environment specific options by accessing config.mongoid. The
 ``mongoid:config`` generator will create an initializer in
 ``config/initializers/mongoid.rb`` which can also be used for configuring
-ActiveDocument. Note, though, that options set in your ``config/activedocument.yml`` will
+ActiveDocument. Note, though, that options set in your ``config/active_document.yml`` will
 take precedence over options set elsewhere; it is recommended that whenever
-possible you use ``activedocument.yml`` as the default location for ActiveDocument
+possible you use ``active_document.yml`` as the default location for ActiveDocument
 configuration.
 
 .. code-block:: ruby
diff --git a/docs/release-notes/mongoid-5.txt b/docs/release-notes/mongoid-5.txt
index 3bd63e4f0..3a48d3b28 100644
--- a/docs/release-notes/mongoid-5.txt
+++ b/docs/release-notes/mongoid-5.txt
@@ -30,7 +30,7 @@ from Moped to the official MongoDB Ruby driver. Please see the
 :ref:`configuration section <configuration>` for a detailed description
 of all the new options.
 
-All references to session are now replaced with client. This includes the ``activedocument.yml``
+All references to session are now replaced with client. This includes the ``active_document.yml``
 configuration, ``store_in`` options, and all exceptions and modules with Session in the name.
 
 ``find_and_modify`` has been removed and replaced with 3 options: ``find_one_and_update``,
diff --git a/docs/release-notes/mongoid-7.4.txt b/docs/release-notes/mongoid-7.4.txt
index 7af520c99..3a5555a6f 100644
--- a/docs/release-notes/mongoid-7.4.txt
+++ b/docs/release-notes/mongoid-7.4.txt
@@ -44,7 +44,7 @@ introduces feature flags which are further explained in the
 sections below.
 
 To enable all new behavior in ActiveDocument 7.4, please use the following
-:ref:`configuration options <configuration-options>` in your activedocument.yml file.
+:ref:`configuration options <configuration-options>` in your active_document.yml file.
 We recommend newly created apps to do this as well.
 
 .. code-block:: yaml
diff --git a/docs/release-notes/mongoid-7.5.txt b/docs/release-notes/mongoid-7.5.txt
index 8985a3ea8..f65bfbfe0 100644
--- a/docs/release-notes/mongoid-7.5.txt
+++ b/docs/release-notes/mongoid-7.5.txt
@@ -34,7 +34,7 @@ introduces feature flags which are further explained in the
 sections below.
 
 To enable all new behavior in ActiveDocument 7.5, please use the following
-:ref:`configuration options <configuration-options>` in your activedocument.yml file.
+:ref:`configuration options <configuration-options>` in your active_document.yml file.
 We recommend newly created apps to do this as well.
 
 .. code-block:: yaml
diff --git a/docs/tutorials/automatic-encryption.txt b/docs/tutorials/automatic-encryption.txt
index 7e3e86267..da0a21072 100644
--- a/docs/tutorials/automatic-encryption.txt
+++ b/docs/tutorials/automatic-encryption.txt
@@ -79,7 +79,7 @@ The steps required are as follows:
 5. Click Download.
 
 Once extracted, ensure the full path to the library is configured within your
-``activedocument.yml`` as follows:
+``active_document.yml`` as follows:
 
 .. code-block:: yaml
 
@@ -142,7 +142,7 @@ Configure Clients
 
 Automatic CSFLE requires some additional configuration for the MongoDB client.
 Assuming that your application has just one ``default`` client, you need to
-add the following to your ``activedocument.yml``:
+add the following to your ``active_document.yml``:
 
 .. code-block:: yaml
 
@@ -248,7 +248,7 @@ Now we can tell ActiveDocument what should be encrypted:
 
 .. note::
   If you are developing a Rails application, it is recommended to set
-  ``preload_models`` to ``true`` in ``activedocument.yml``. This will ensure that
+  ``preload_models`` to ``true`` in ``active_document.yml``. This will ensure that
   ActiveDocument loads all models before the application starts, and the encryption
   schema is configured before any data is read or written.
 
@@ -340,7 +340,7 @@ Data Encryption Keys can be created using the
 ``db:mongoid:encryption:create_data_key`` ``Rake`` task. By default they are
 stored on the same cluster as the database.
 However, it might be a good idea to store the keys separately. This can be
-done by specifying a key vault client in ``activedocument.yml``:
+done by specifying a key vault client in ``active_document.yml``:
 
 .. code-block:: yaml
 
@@ -376,7 +376,7 @@ Here is an example of rotating keys using AWS KMS:
 
   # Create a key vault client
   key_vault_client = Mongo::Client.new('mongodb+srv://user:pass@yourcluster.mongodb.net')
-  # Or, if you declared the key value client in activedocument.yml, use it
+  # Or, if you declared the key value client in active_document.yml, use it
   key_vault_client = ActiveDocument.client(:key_vault)
 
   # Create the encryption object
diff --git a/docs/tutorials/getting-started-rails6.txt b/docs/tutorials/getting-started-rails6.txt
index 3821687b1..79bbf5d88 100644
--- a/docs/tutorials/getting-started-rails6.txt
+++ b/docs/tutorials/getting-started-rails6.txt
@@ -125,7 +125,7 @@ Add ActiveDocument
 
     bin/rails g mongoid:config
 
-This generator will create the ``config/activedocument.yml`` configuration file
+This generator will create the ``config/active_document.yml`` configuration file
 (used to configure the connection to the MongoDB deployment) and the
 ``config/initializers/mongoid.rb`` initializer file (which may be used for
 other ActiveDocument-related configuration). Note that as we are not using
@@ -142,9 +142,9 @@ a MongoDB server is running locally. If you do not already have a
 local MongoDB server, `download and install MongoDB
 <https://mongodb.com/docs/manual/installation/>`_.
 
-While the generated ``activedocument.yml`` will work without modifications,
+While the generated ``active_document.yml`` will work without modifications,
 we recommend reducing the server selection timeout for development.
-With this change, the uncommented lines of ``activedocument.yml`` should look
+With this change, the uncommented lines of ``active_document.yml`` should look
 like this:
 
 .. code-block:: none
@@ -171,11 +171,11 @@ Once the cluster is created, follow the instructions in `connect to the cluster
 page <https://docs.atlas.mongodb.com/connect-to-cluster/#connect-to-a-cluster>`_
 to obtain the URI. Use the *Ruby driver 2.5 or later* format.
 
-Paste the URI into the ``config/activedocument.yml`` file, and comment out the
+Paste the URI into the ``config/active_document.yml`` file, and comment out the
 hosts that are defined. We recommend setting the server selection timeout to 5
 seconds for development environment when using Atlas.
 
-The uncommented contents of ``config/activedocument.yml`` should look like this:
+The uncommented contents of ``config/active_document.yml`` should look like this:
 
 .. code-block:: yaml
 
@@ -466,15 +466,15 @@ Generate the default ActiveDocument configuration:
 
     bin/rails g mongoid:config
 
-This generator will create the ``config/activedocument.yml`` configuration file
+This generator will create the ``config/active_document.yml`` configuration file
 (used to configure the connection to the MongoDB deployment) and the
 ``config/initializers/mongoid.rb`` initializer file (which may be used for
 other ActiveDocument-related configuration). In general, it is recommended to use
-``activedocument.yml`` for all ActiveDocument configuration.
+``active_document.yml`` for all ActiveDocument configuration.
 
 Review the sections :ref:`Run MongoDB Locally <run-locally>` and
 :ref:`Use MongoDB Atlas <use-atlas>` to decide how you would like to deploy
-MongoDB, and adjust ActiveDocument configuration (``config/activedocument.yml``) to match.
+MongoDB, and adjust ActiveDocument configuration (``config/active_document.yml``) to match.
 
 Adjust Models
 -------------
diff --git a/docs/tutorials/getting-started-rails7.txt b/docs/tutorials/getting-started-rails7.txt
index bc21d28c0..338b9e9bc 100644
--- a/docs/tutorials/getting-started-rails7.txt
+++ b/docs/tutorials/getting-started-rails7.txt
@@ -95,7 +95,7 @@ Setup ActiveDocument
 
     bin/rails g mongoid:config
 
-This generator will create the ``config/activedocument.yml`` configuration file
+This generator will create the ``config/active_document.yml`` configuration file
 (used to configure the connection to the MongoDB deployment) and the
 ``config/initializers/mongoid.rb`` initializer file (which may be used for
 other ActiveDocument-related configuration). Note that as we are not using
@@ -112,9 +112,9 @@ a MongoDB server is running locally. If you do not already have a
 local MongoDB server, `download and install MongoDB
 <https://mongodb.com/docs/manual/installation/>`_.
 
-While the generated ``activedocument.yml`` will work without modifications,
+While the generated ``active_document.yml`` will work without modifications,
 we recommend reducing the server selection timeout for development.
-With this change, the uncommented lines of ``activedocument.yml`` should look
+With this change, the uncommented lines of ``active_document.yml`` should look
 like this:
 
 .. code-block:: yaml
@@ -141,11 +141,11 @@ Once the cluster is created, follow the instructions in `connect to the cluster
 page <https://docs.atlas.mongodb.com/connect-to-cluster/#connect-to-a-cluster>`_
 to obtain the URI. Use the *Ruby driver 2.5 or later* format.
 
-Paste the URI into the ``config/activedocument.yml`` file, and comment out the
+Paste the URI into the ``config/active_document.yml`` file, and comment out the
 hosts that are defined. We recommend setting the server selection timeout to 5
 seconds for development environment when using Atlas.
 
-The uncommented contents of ``config/activedocument.yml`` should look like this:
+The uncommented contents of ``config/active_document.yml`` should look like this:
 
 .. code-block:: yaml
 
@@ -334,16 +334,16 @@ Generate the default ActiveDocument configuration:
 
     bin/rails g mongoid:config
 
-This generator will create the ``config/activedocument.yml`` configuration file
+This generator will create the ``config/active_document.yml`` configuration file
 (used to configure the connection to the MongoDB deployment) and the
 ``config/initializers/mongoid.rb`` initializer file (which may be used for
 other ActiveDocument-related configuration). In general, it is recommended to use
-``activedocument.yml`` for all ActiveDocument configuration.
+``active_document.yml`` for all ActiveDocument configuration.
 
 Review the sections :ref:`Configure for Self Managed MongoDB <configure-self-managed>`
 and :ref:`Configure for MongoDB Atlas <configure-atlas>` to decide how you
 would like to deploy MongoDB, and adjust the ActiveDocument configuration
-(``config/activedocument.yml``) to match.
+(``config/active_document.yml``) to match.
 
 Loaded Frameworks
 -----------------
diff --git a/docs/tutorials/getting-started-sinatra.txt b/docs/tutorials/getting-started-sinatra.txt
index 3a5dae84a..7c5fd029c 100644
--- a/docs/tutorials/getting-started-sinatra.txt
+++ b/docs/tutorials/getting-started-sinatra.txt
@@ -69,7 +69,7 @@ Run MongoDB Locally
 To develop locally with MongoDB, `download and install MongoDB
 <https://mongodb.com/docs/manual/installation/>`_.
 
-Once MongoDB is installed and running, create a file named ``config/activedocument.yml``
+Once MongoDB is installed and running, create a file named ``config/active_document.yml``
 pointing to your deployment. For example, if you launched a standalone
 ``mongod`` on the default port, the following contents would be appropriate:
 
@@ -95,7 +95,7 @@ Once the cluster is created, follow the instructions in `connect to the cluster
 page <https://docs.atlas.mongodb.com/connect-to-cluster/#connect-to-a-cluster>`_
 to obtain the URI. Use the *Ruby driver 2.5 or later* format.
 
-Create a file named ``config/activedocument.yml`` with the following
+Create a file named ``config/active_document.yml`` with the following
 contents, replacing the URI with the actual URI for your cluster:
 
 .. code-block:: yaml
@@ -126,7 +126,7 @@ with Sinatra, we need to do this ourselves:
 
 .. code-block:: ruby
 
-    ActiveDocument.load!(File.join(File.dirname(__FILE__), 'config', 'activedocument.yml'))
+    ActiveDocument.load!(File.join(File.dirname(__FILE__), 'config', 'active_document.yml'))
 
 Now we can define some models:
 
@@ -213,6 +213,6 @@ To start using ActiveDocument in an existing Sinatra applications, the steps are
 essentially the same as the one given above for a new application:
 
 1. Add the ``mongoid`` dependency to the ``Gemfile``.
-2. Create a ``activedocument.yml`` configuration file.
+2. Create a ``active_document.yml`` configuration file.
 3. Load the configuration file and configure ActiveDocument in the application.
 4. Define ActiveDocument models.
diff --git a/lib/active_document.rb b/lib/active_document.rb
index 7813746ec..d955fb159 100644
--- a/lib/active_document.rb
+++ b/lib/active_document.rb
@@ -46,7 +46,7 @@ module ActiveDocument
   extend Clients::Sessions::ClassMethods
 
   # A string added to the platform details of Ruby driver client handshake documents.
-  PLATFORM_DETAILS = "mongoid-#{VERSION}".freeze # rubocop:disable Style/RedundantFreeze
+  PLATFORM_DETAILS = "active_document-#{VERSION}".freeze # rubocop:disable Style/RedundantFreeze
 
   # The minimum MongoDB version supported.
   MONGODB_VERSION = '2.6.0'
@@ -55,11 +55,11 @@ module ActiveDocument
   #
   # @example Set up configuration options.
   #   ActiveDocument.configure do |config|
-  #     config.connect_to("mongoid_test")
+  #     config.connect_to("active_document_test")
   #
   #     config.clients.default = {
   #       hosts: ["localhost:27017"],
-  #       database: "mongoid_test",
+  #       database: "active_document_test",
   #     }
   #   end
   #
@@ -67,7 +67,7 @@ module ActiveDocument
   #   the block to perform variable assignment.
   #
   #   ActiveDocument.configure do
-  #     connect_to("mongoid_test")
+  #     connect_to("active_document_test")
   #
   #     config.preload_models = true
   #
diff --git a/lib/active_document/association/accessors.rb b/lib/active_document/association/accessors.rb
index 780643be1..a447258f3 100644
--- a/lib/active_document/association/accessors.rb
+++ b/lib/active_document/association/accessors.rb
@@ -294,7 +294,7 @@ def get_relation(name, association, object, reload = false) # rubocop:disable St
               if object && needs_no_database_query?(object, association)
                 __build__(name, object, association)
               else
-                selected_fields = _mongoid_filter_selected_fields(association.key)
+                selected_fields = _active_document_filter_selected_fields(association.key)
                 __build__(name, attributes[association.key], association, selected_fields)
               end
             end
@@ -317,7 +317,7 @@ def get_relation(name, association, object, reload = false) # rubocop:disable St
       # @return [ Hash | nil ]
       #
       # @api private
-      def _mongoid_filter_selected_fields(assoc_key)
+      def _active_document_filter_selected_fields(assoc_key)
         return nil unless __selected_fields
 
         # If the list of fields was specified using #without instead of #only
diff --git a/lib/active_document/config.rb b/lib/active_document/config.rb
index 405fcedab..e3175ba46 100644
--- a/lib/active_document/config.rb
+++ b/lib/active_document/config.rb
@@ -185,7 +185,7 @@ def configured?
     # @note Use only in development or test environments for convenience.
     #
     # @example Set the database to connect to.
-    #   config.connect_to("mongoid_test")
+    #   config.connect_to("active_document_test")
     #
     # @param [ String ] name The database name.
     def connect_to(name, options = { read: { mode: :primary } })
@@ -209,11 +209,11 @@ def destructive_fields
       Composable.prohibited_methods
     end
 
-    # Load the settings from a compliant activedocument.yml file. This can be used for
+    # Load the settings from a compliant active_document.yml file. This can be used for
     # easy setup with frameworks other than Rails.
     #
     # @example Configure ActiveDocument.
-    #   ActiveDocument.load!("/path/to/activedocument.yml")
+    #   ActiveDocument.load!("/path/to/active_document.yml")
     #
     # @param [ String ] path The path to the file.
     # @param [ String | Symbol ] environment The environment to load.
diff --git a/lib/active_document/config/environment.rb b/lib/active_document/config/environment.rb
index 04e66909d..c1cbef06e 100644
--- a/lib/active_document/config/environment.rb
+++ b/lib/active_document/config/environment.rb
@@ -34,7 +34,7 @@ def env_name
       # specified environment, or for the current ActiveDocument environment.
       #
       # @example Load the yaml.
-      #   Environment.load_yaml("/work/activedocument.yml")
+      #   Environment.load_yaml("/work/active_document.yml")
       #
       # @param [ String ] path The location of the file.
       # @param [ String | Symbol ] environment Optional environment name to
diff --git a/lib/active_document/config/introspection.rb b/lib/active_document/config/introspection.rb
index 8d5229fcb..a61954985 100644
--- a/lib/active_document/config/introspection.rb
+++ b/lib/active_document/config/introspection.rb
@@ -6,7 +6,7 @@ module Config
     # This module provides a way to inspect not only the defined configuration
     # settings and their defaults (which are available via
     # `ActiveDocument::Config.settings`), but also the documentation about them. It
-    # does this by scraping the `mongoid/config.rb` file with a regular
+    # does this by scraping the `active_document/config.rb` file with a regular
     # expression to match comments with options.
     #
     # @api private
@@ -28,7 +28,7 @@ class Option
         attr_reader :default
 
         # The comment that describes this option, as scraped from
-        # mongoid/config.rb.
+        # active_document/config.rb.
         #
         # @return [ String ] The (possibly multi-line) comment. Each line is
         #   prefixed with the Ruby comment character ("#").
diff --git a/lib/active_document/criteria/modifiable.rb b/lib/active_document/criteria/modifiable.rb
index c15313c29..25dec5b28 100644
--- a/lib/active_document/criteria/modifiable.rb
+++ b/lib/active_document/criteria/modifiable.rb
@@ -220,13 +220,13 @@ def first_or(method, attrs = {}, &block)
 
       def invalid_key?(hash, key)
         # @todo Change this to BSON::String::ILLEGAL_KEY when ruby driver 2.3.0 is
-        # released and mongoid is updated to depend on driver >= 2.3.0
+        # released and active_document is updated to depend on driver >= 2.3.0
         key.to_s =~ ActiveDocument::Document::ILLEGAL_KEY || hash.key?(key.to_sym) || hash.key?(key)
       end
 
       def invalid_embedded_doc?(value)
         # @todo Change this to BSON::String::ILLEGAL_KEY when ruby driver 2.3.0 is
-        # released and mongoid is updated to depend on driver >= 2.3.0
+        # released and active_document is updated to depend on driver >= 2.3.0
         value.is_a?(Hash) && value.any? do |key, v|
           key.to_s =~ ActiveDocument::Document::ILLEGAL_KEY || invalid_embedded_doc?(v)
         end
diff --git a/lib/active_document/criteria/queryable/mergeable.rb b/lib/active_document/criteria/queryable/mergeable.rb
index 1069d0f69..19eaba00d 100644
--- a/lib/active_document/criteria/queryable/mergeable.rb
+++ b/lib/active_document/criteria/queryable/mergeable.rb
@@ -164,7 +164,7 @@ def __multi__(criteria, operator)
               if expr.is_a?(Selectable)
                 expr = expr.selector
               end
-              normalized = _mongoid_expand_keys(expr)
+              normalized = _active_document_expand_keys(expr)
               sel.store(operator, result_criteria.push(normalized))
             end
           end
@@ -180,7 +180,7 @@ def __multi__(criteria, operator)
         # - nil, in which case it is ignored
         #
         # @api private
-        def _mongoid_add_top_level_operation(operator, criteria)
+        def _active_document_add_top_level_operation(operator, criteria)
           # Flatten the criteria. The idea is that predicates in MongoDB
           # are always hashes and are never arrays. This method additionally
           # allows Criteria instances as predicates.
@@ -189,11 +189,11 @@ def _mongoid_add_top_level_operation(operator, criteria)
           # flatten if needed.
           clone.tap do |query|
             sel = query.selector
-            _mongoid_flatten_arrays(criteria).each do |criterion|
+            _active_document_flatten_arrays(criteria).each do |criterion|
               expr = if criterion.is_a?(Selectable)
-                       _mongoid_expand_keys(criterion.selector)
+                       _active_document_expand_keys(criterion.selector)
                      else
-                       _mongoid_expand_keys(criterion)
+                       _active_document_expand_keys(criterion)
                      end
               if sel.empty?
                 sel.store(operator, [expr])
@@ -211,7 +211,7 @@ def _mongoid_add_top_level_operation(operator, criteria)
         # Calling .flatten on an array which includes a Criteria instance
         # evaluates the criteria, which we do not want. Hence this method
         # explicitly only expands Array objects and Array subclasses.
-        def _mongoid_flatten_arrays(array)
+        def _active_document_flatten_arrays(array)
           out = []
           pending = array.dup
           until pending.empty?
@@ -254,7 +254,7 @@ def _mongoid_flatten_arrays(array)
         # @param [ Hash ] expr Criteria including Key instances.
         #
         # @return [ BSON::Document ] The expanded criteria.
-        def _mongoid_expand_keys(expr)
+        def _active_document_expand_keys(expr)
           unless expr.is_a?(Hash)
             raise ArgumentError.new('Argument must be a Hash')
           end
diff --git a/lib/active_document/criteria/queryable/selectable.rb b/lib/active_document/criteria/queryable/selectable.rb
index 9ab7b7115..f2ada4145 100644
--- a/lib/active_document/criteria/queryable/selectable.rb
+++ b/lib/active_document/criteria/queryable/selectable.rb
@@ -67,9 +67,9 @@ def all(*criteria)
         #
         # @return [ Selectable ] The new selectable.
         def and(*criteria)
-          _mongoid_flatten_arrays(criteria).inject(clone) do |c, new_s|
+          _active_document_flatten_arrays(criteria).inject(clone) do |c, new_s|
             new_s = new_s.selector if new_s.is_a?(Selectable)
-            normalized = _mongoid_expand_keys(new_s)
+            normalized = _active_document_expand_keys(new_s)
             normalized.each do |k, v|
               k = k.to_s
               if c.selector[k]
@@ -475,7 +475,7 @@ def nin(condition)
         #
         # @return [ Selectable ] The new selectable.
         def nor(*criteria)
-          _mongoid_add_top_level_operation('$nor', criteria)
+          _active_document_add_top_level_operation('$nor', criteria)
         end
 
         # Is the current selectable negating the next selection?
@@ -509,7 +509,7 @@ def not(*criteria)
           else
             criteria.compact.inject(clone) do |c, new_s|
               new_s = new_s.selector if new_s.is_a?(Selectable)
-              _mongoid_expand_keys(new_s).each do |k, v|
+              _active_document_expand_keys(new_s).each do |k, v|
                 k = k.to_s
                 if c.selector[k] || k.start_with?('$') || v.is_a?(Hash)
                   c = c.send(:__multi__, [{ '$nor' => [{ k => v }] }], '$and')
@@ -545,11 +545,11 @@ def not(*criteria)
         #
         # @return [ Selectable ] The new selectable.
         def none_of(*criteria)
-          criteria = _mongoid_flatten_arrays(criteria)
+          criteria = _active_document_flatten_arrays(criteria)
           return dup if criteria.empty?
 
           exprs = criteria.map do |criterion|
-            _mongoid_expand_keys(
+            _active_document_expand_keys(
               criterion.is_a?(Selectable) ? criterion.selector : criterion
             )
           end
@@ -588,7 +588,7 @@ def none_of(*criteria)
         #
         # @return [ Selectable ] The new selectable.
         def or(*criteria)
-          _mongoid_add_top_level_operation('$or', criteria)
+          _active_document_add_top_level_operation('$or', criteria)
         end
 
         # Adds a disjunction of the arguments as an additional constraint
@@ -618,7 +618,7 @@ def or(*criteria)
         #
         # @return [ Selectable ] The new selectable.
         def any_of(*criteria)
-          criteria = _mongoid_flatten_arrays(criteria)
+          criteria = _active_document_flatten_arrays(criteria)
           case criteria.length
           when 0
             clone
@@ -632,7 +632,7 @@ def any_of(*criteria)
             # and add the result to self.
             exprs = criteria.map do |criterion|
               if criterion.is_a?(Selectable)
-                _mongoid_expand_keys(criterion.selector)
+                _active_document_expand_keys(criterion.selector)
               else
                 criterion.to_h do |k, v|
                   if k.is_a?(Symbol)
@@ -800,7 +800,7 @@ def expr_query(criterion)
             raise Errors::InvalidQuery.new("Expression must be a Hash: #{Errors::InvalidQuery.truncate_expr(criterion)}")
           end
 
-          normalized = _mongoid_expand_keys(criterion)
+          normalized = _active_document_expand_keys(criterion)
           clone.tap do |query|
             normalized.each do |field, value|
               field_s = field.to_s
diff --git a/lib/active_document/document.rb b/lib/active_document/document.rb
index f295aca57..63641658b 100644
--- a/lib/active_document/document.rb
+++ b/lib/active_document/document.rb
@@ -148,7 +148,7 @@ def as_document
     #
     # @return [ ActiveDocument::Document ] An instance of the specified class.
     def becomes(klass)
-      mongoid_document_check!(klass)
+      active_document_document_check!(klass)
 
       became = klass.new(clone_document)
       became.internal_state = internal_state
@@ -297,7 +297,7 @@ def add_attributes_for_relation(name, meta)
     #
     # @raise [ ArgumentError ] if the class does not include
     #   ActiveDocument::Document.
-    def mongoid_document_check!(klass)
+    def active_document_document_check!(klass)
       return if klass.include?(ActiveDocument::Document)
 
       raise ArgumentError.new('A class which includes ActiveDocument::Document is expected')
@@ -457,19 +457,19 @@ def _types
       # key/value on a class.
       #
       # @example Get the types.
-      #   document._mongoid_clear_types
+      #   document._active_document_clear_types
       #
       # @api private
-      def _mongoid_clear_types
+      def _active_document_clear_types
         @_types = nil
-        superclass._mongoid_clear_types if hereditary?
+        superclass._active_document_clear_types if hereditary?
       end
 
       # Set the i18n scope to overwrite ActiveModel.
       #
-      # @return [ Symbol ] :mongoid
+      # @return [ Symbol ] :active_document
       def i18n_scope
-        :mongoid
+        :active_document
       end
 
       # Returns the logger
@@ -485,4 +485,4 @@ def logger
   end
 end
 
-ActiveSupport.run_load_hooks(:mongoid, ActiveDocument::Document)
+ActiveSupport.run_load_hooks(:active_document, ActiveDocument::Document)
diff --git a/lib/active_document/errors/base_error.rb b/lib/active_document/errors/base_error.rb
index 9b369bfa3..d5da60c7d 100644
--- a/lib/active_document/errors/base_error.rb
+++ b/lib/active_document/errors/base_error.rb
@@ -10,7 +10,7 @@ class BaseError < StandardError
 
       attr_reader :problem, :summary, :resolution
 
-      BASE_KEY = 'mongoid.errors.messages'
+      BASE_KEY = 'active_document.errors.messages'
 
       # Compose the message.
       #
diff --git a/lib/active_document/extensions/string.rb b/lib/active_document/extensions/string.rb
index 5a21f9031..654e842ce 100644
--- a/lib/active_document/extensions/string.rb
+++ b/lib/active_document/extensions/string.rb
@@ -66,14 +66,14 @@ def collectionize
       # Is the string a valid value for a ActiveDocument id?
       #
       # @example Is the string an id value?
-      #   "_id".mongoid_id?
+      #   "_id".active_document_id?
       #
       # @return [ true | false ] If the string is id or _id.
       # @deprecated
-      def mongoid_id?
+      def active_document_id?
         self =~ /\A(|_)id\z/
       end
-      ActiveDocument.deprecate(self, :mongoid_id?)
+      ActiveDocument.deprecate(self, :active_document_id?)
 
       # Is the string a number? The literals "NaN", "Infinity", and "-Infinity"
       # are counted as numbers.
diff --git a/lib/active_document/extensions/symbol.rb b/lib/active_document/extensions/symbol.rb
index 68d821dfa..71ee10b92 100644
--- a/lib/active_document/extensions/symbol.rb
+++ b/lib/active_document/extensions/symbol.rb
@@ -9,14 +9,14 @@ module Symbol
       # Is the symbol a valid value for a ActiveDocument id?
       #
       # @example Is the string an id value?
-      #   :_id.mongoid_id?
+      #   :_id.active_document_id?
       #
       # @return [ true | false ] If the symbol is :id or :_id.
       # @deprecated
-      def mongoid_id?
-        to_s.mongoid_id?
+      def active_document_id?
+        to_s.active_document_id?
       end
-      ActiveDocument.deprecate(self, :mongoid_id?)
+      ActiveDocument.deprecate(self, :active_document_id?)
 
       module ClassMethods
 
diff --git a/lib/active_document/interceptable.rb b/lib/active_document/interceptable.rb
index 348be776d..e637a6ace 100644
--- a/lib/active_document/interceptable.rb
+++ b/lib/active_document/interceptable.rb
@@ -153,11 +153,11 @@ def run_callbacks(kind, with_children: true, skip_if: nil, &block)
     #   the document.
     #
     # @api private
-    def _mongoid_run_child_callbacks(kind, children: nil, &block)
+    def _active_document_run_child_callbacks(kind, children: nil, &block)
       if ActiveDocument::Config.around_callbacks_for_embeds
-        _mongoid_run_child_callbacks_with_around(kind, children: children, &block)
+        _active_document_run_child_callbacks_with_around(kind, children: children, &block)
       else
-        _mongoid_run_child_callbacks_without_around(kind, children: children, &block)
+        _active_document_run_child_callbacks_without_around(kind, children: children, &block)
       end
     end
 
@@ -175,7 +175,7 @@ def _mongoid_run_child_callbacks(kind, children: nil, &block)
     #  the document.
     #
     #  @api private
-    def _mongoid_run_child_callbacks_with_around(kind, children: nil, &block)
+    def _active_document_run_child_callbacks_with_around(kind, children: nil, &block)
       child, *tail = children || cascadable_children(kind)
       with_children = !ActiveDocument::Config.prevent_multiple_calls_of_embedded_callbacks
       if child.nil?
@@ -184,7 +184,7 @@ def _mongoid_run_child_callbacks_with_around(kind, children: nil, &block)
         child.run_callbacks(child_callback_type(kind, child), with_children: with_children, &block)
       else
         child.run_callbacks(child_callback_type(kind, child), with_children: with_children) do
-          _mongoid_run_child_callbacks_with_around(kind, children: tail, &block)
+          _active_document_run_child_callbacks_with_around(kind, children: tail, &block)
         end
       end
     end
@@ -198,16 +198,16 @@ def _mongoid_run_child_callbacks_with_around(kind, children: nil, &block)
     #   the document.
     #
     # @api private
-    def _mongoid_run_child_callbacks_without_around(kind, children: nil, &block)
+    def _active_document_run_child_callbacks_without_around(kind, children: nil, &block)
       children ||= cascadable_children(kind)
-      callback_list = _mongoid_run_child_before_callbacks(kind, children: children)
+      callback_list = _active_document_run_child_before_callbacks(kind, children: children)
       return false if callback_list == false
 
       value = block&.call
       callback_list.each do |_next_sequence, env| # rubocop:disable Style/HashEachMethods
         env.value &&= value
       end
-      return false if _mongoid_run_child_after_callbacks(callback_list: callback_list) == false
+      return false if _active_document_run_child_after_callbacks(callback_list: callback_list) == false
 
       value
     end
@@ -221,7 +221,7 @@ def _mongoid_run_child_callbacks_without_around(kind, children: nil, &block)
     #   to execute after callbacks in reverse order.
     #
     # @api private
-    def _mongoid_run_child_before_callbacks(kind, children: [], callback_list: [])
+    def _active_document_run_child_before_callbacks(kind, children: [], callback_list: [])
       children.each do |child|
         chain = child.__callbacks[child_callback_type(kind, child)]
         env = ActiveSupport::Callbacks::Filters::Environment.new(child, false, nil)
@@ -236,7 +236,7 @@ def _mongoid_run_child_before_callbacks(kind, children: [], callback_list: [])
         env.value = !env.halted
         callback_list << [next_sequence, env]
         if (grandchildren = child.send(:cascadable_children, kind))
-          _mongoid_run_child_before_callbacks(kind, children: grandchildren, callback_list: callback_list)
+          _active_document_run_child_before_callbacks(kind, children: grandchildren, callback_list: callback_list)
         end
       end
       callback_list
@@ -246,7 +246,7 @@ def _mongoid_run_child_before_callbacks(kind, children: [], callback_list: [])
     #
     # @param [ Array<ActiveSupport::Callbacks::CallbackSequence, ActiveSupport::Callbacks::Filters::Environment> ] callback_list List of
     #   pairs of callback sequence and environment.
-    def _mongoid_run_child_after_callbacks(callback_list: [])
+    def _active_document_run_child_after_callbacks(callback_list: [])
       callback_list.reverse_each do |next_sequence, env|
         next_sequence.invoke_after(env)
         return false if env.halted
diff --git a/lib/active_document/persistable.rb b/lib/active_document/persistable.rb
index 155768510..141edbe69 100644
--- a/lib/active_document/persistable.rb
+++ b/lib/active_document/persistable.rb
@@ -95,7 +95,7 @@ def atomically(join_context: nil)
       call_depth = @atomic_depth ||= 0
       has_own_context = call_depth.zero? || !join_context
       @atomic_updates_to_execute_stack ||= []
-      _mongoid_push_atomic_context if has_own_context
+      _active_document_push_atomic_context if has_own_context
 
       if block_given?
         @atomic_depth += 1
@@ -105,15 +105,15 @@ def atomically(join_context: nil)
 
       if has_own_context
         persist_atomic_operations @atomic_context
-        _mongoid_remove_atomic_context_changes
+        _active_document_remove_atomic_context_changes
       end
 
       true
     rescue StandardError => e
-      _mongoid_reset_atomic_context_changes! if has_own_context
+      _active_document_reset_atomic_context_changes! if has_own_context
       raise e
     ensure
-      _mongoid_pop_atomic_context if has_own_context
+      _active_document_pop_atomic_context if has_own_context
 
       if call_depth.zero?
         @atomic_depth = nil
@@ -224,11 +224,11 @@ def process_atomic_operations(operations)
     # @api private
     #
     # @example Remove the current atomic context's dirty changes.
-    #   document._mongoid_remove_atomic_context_changes
-    def _mongoid_remove_atomic_context_changes
+    #   document._active_document_remove_atomic_context_changes
+    def _active_document_remove_atomic_context_changes
       return unless executing_atomically?
 
-      _mongoid_atomic_context_changed_fields.each { |f| remove_change f }
+      _active_document_atomic_context_changed_fields.each { |f| remove_change f }
     end
 
     # Reset the attributes for all fields changed in the current atomic
@@ -237,11 +237,11 @@ def _mongoid_remove_atomic_context_changes
     # @api private
     #
     # @example Reset the current atomic context's changed attributes.
-    #   document._mongoid_reset_atomic_context_changes!
-    def _mongoid_reset_atomic_context_changes!
+    #   document._active_document_reset_atomic_context_changes!
+    def _active_document_reset_atomic_context_changes!
       return unless executing_atomically?
 
-      _mongoid_atomic_context_changed_fields.each { |f| reset_attribute! f }
+      _active_document_atomic_context_changed_fields.each { |f| reset_attribute! f }
     end
 
     # Push a new atomic context onto the stack.
@@ -249,8 +249,8 @@ def _mongoid_reset_atomic_context_changes!
     # @api private
     #
     # @example Push a new atomic context onto the stack.
-    #   document._mongoid_push_atomic_context
-    def _mongoid_push_atomic_context
+    #   document._active_document_push_atomic_context
+    def _active_document_push_atomic_context
       return unless executing_atomically?
 
       @atomic_context = {}
@@ -262,8 +262,8 @@ def _mongoid_push_atomic_context
     # @api private
     #
     # @example Pop an atomic context off the stack.
-    #   document._mongoid_pop_atomic_context
-    def _mongoid_pop_atomic_context
+    #   document._active_document_pop_atomic_context
+    def _active_document_pop_atomic_context
       return unless executing_atomically?
 
       @atomic_updates_to_execute_stack.pop
@@ -275,10 +275,10 @@ def _mongoid_pop_atomic_context
     # @api private
     #
     # @example Return the current atomic context's changed fields.
-    #   document._mongoid_atomic_context_changed_fields
+    #   document._active_document_atomic_context_changed_fields
     #
     # @return [ Array ] The changed fields.
-    def _mongoid_atomic_context_changed_fields
+    def _active_document_atomic_context_changed_fields
       @atomic_context.values.flat_map(&:keys)
     end
 
diff --git a/lib/active_document/persistable/creatable.rb b/lib/active_document/persistable/creatable.rb
index 466ce4b97..6fcfed0b3 100644
--- a/lib/active_document/persistable/creatable.rb
+++ b/lib/active_document/persistable/creatable.rb
@@ -112,8 +112,8 @@ def prepare_insert(options = {})
           run_callbacks(:save, with_children: false) do
             run_callbacks(:create, with_children: false) do
               run_callbacks(:persist_parent, with_children: false) do
-                _mongoid_run_child_callbacks(:save) do
-                  _mongoid_run_child_callbacks(:create) do
+                _active_document_run_child_callbacks(:save) do
+                  _active_document_run_child_callbacks(:create) do
                     result = yield(self)
                     if !result.is_a?(Document) || result.errors.empty?
                       post_process_insert
diff --git a/lib/active_document/persistable/updatable.rb b/lib/active_document/persistable/updatable.rb
index 1aab2064d..8bd01281f 100644
--- a/lib/active_document/persistable/updatable.rb
+++ b/lib/active_document/persistable/updatable.rb
@@ -217,8 +217,8 @@ def run_all_callbacks_for_update(update_children, &block)
           run_callbacks(:save, with_children: false) do
             run_callbacks(:update, with_children: false) do
               run_callbacks(:persist_parent, with_children: false) do
-                _mongoid_run_child_callbacks(:save) do
-                  _mongoid_run_child_callbacks(:update, children: update_children, &block)
+                _active_document_run_child_callbacks(:save) do
+                  _active_document_run_child_callbacks(:update, children: update_children, &block)
                 end
               end
             end
diff --git a/lib/active_document/persistence_context.rb b/lib/active_document/persistence_context.rb
index a4df9fc36..b4001123d 100644
--- a/lib/active_document/persistence_context.rb
+++ b/lib/active_document/persistence_context.rb
@@ -152,7 +152,7 @@ def ==(other)
     # not be closed.
     #
     # If the persistence context is requested with :client option only, it means
-    # that the context should use a client configured in activedocument.yml.
+    # that the context should use a client configured in active_document.yml.
     # Such clients should not be closed when the context is cleared since they
     # will be reused later.
     #
@@ -276,7 +276,7 @@ def clear(object, cluster = nil, original_context = nil)
       # Key to store persistence contexts in the thread local storage.
       #
       # @api private
-      PERSISTENCE_CONTEXT_KEY = :'[mongoid]:persistence_context'
+      PERSISTENCE_CONTEXT_KEY = :'[active_document]:persistence_context'
 
       # Get the persistence context for a given object from the thread local
       #   storage.
diff --git a/lib/active_document/railtie.rb b/lib/active_document/railtie.rb
index 3e7d5800d..79393746b 100644
--- a/lib/active_document/railtie.rb
+++ b/lib/active_document/railtie.rb
@@ -29,12 +29,12 @@ def self.rescue_responses
         }
       end
 
-      config.app_generators.orm :mongoid, migration: false
+      config.app_generators.orm :active_document, migration: false
 
       config.action_dispatch.rescue_responses&.merge!(rescue_responses)
 
       rake_tasks do
-        load 'mongoid/railties/database.rake'
+        load 'active_document/railties/database.rake'
       end
 
       # Exposes ActiveDocument's configuration to the Rails application configuration.
@@ -42,19 +42,19 @@ def self.rescue_responses
       # @example Set up configuration in the Rails app.
       #   module MyApplication
       #     class Application < Rails::Application
-      #       config.mongoid.logger = Logger.new(STDERR, :warn)
+      #       config.active_document.logger = Logger.new(STDERR, :warn)
       #     end
       #   end
-      config.mongoid = ::ActiveDocument::Config
+      config.active_document = ::ActiveDocument::Config
 
-      # Initialize ActiveDocument. This will look for a activedocument.yml in the config
-      # directory and configure mongoid appropriately.
+      # Initialize ActiveDocument. This will look for a active_document.yml in the config
+      # directory and configure active_document appropriately.
       #
       # It runs after all config/initializers have loaded, so that the YAML
       # options can override options specified in
-      # (e.g.) config/initializers/mongoid.rb.
-      initializer 'mongoid.load-config', after: :load_config_initializers do
-        config_file = Rails.root.join('config/activedocument.yml')
+      # (e.g.) config/initializers/active_document.rb.
+      initializer 'active_document.load-config', after: :load_config_initializers do
+        config_file = Rails.root.join('config/active_document.yml')
         if config_file.file?
           begin
             ::ActiveDocument.load!(config_file)
@@ -81,7 +81,7 @@ def self.rescue_responses
       #
       # This will happen for every request in development, once in other
       # environments.
-      initializer 'mongoid.preload-models' do |app|
+      initializer 'active_document.preload-models' do |app|
         config.to_prepare do
           ::Rails::ActiveDocument.preload_models(app)
         end
@@ -89,10 +89,10 @@ def self.rescue_responses
 
       # Rails runs all initializers first before getting into any generator
       # code, so we have no way in the initializer to know if we are
-      # generating a activedocument.yml. So instead of failing, we catch all the
+      # generating a active_document.yml. So instead of failing, we catch all the
       # errors and print them out.
       def handle_configuration_error(error)
-        ::ActiveDocument.logger.error 'There is a configuration error with the current activedocument.yml.'
+        ::ActiveDocument.logger.error 'There is a configuration error with the current active_document.yml.'
         ::ActiveDocument.logger.error error.message
       end
 
@@ -101,7 +101,7 @@ def handle_configuration_error(error)
       # instrumentation event `process_action.action_controller`.
       #
       # The measurement is made via internal Mongo monitoring subscription
-      initializer 'mongoid.runtime-metric' do
+      initializer 'active_document.runtime-metric' do
         require 'active_document/railties/controller_runtime'
 
         ActiveSupport.on_load :action_controller do
@@ -113,7 +113,7 @@ def handle_configuration_error(error)
       end
 
       # Add custom serializers for BSON::ObjectId
-      initializer 'mongoid.active_job.custom_serializers' do
+      initializer 'active_document.active_job.custom_serializers' do
         ActiveSupport.on_load :active_job do
           require 'active_document/railties/bson_object_id_serializer'
 
diff --git a/lib/active_document/railties/controller_runtime.rb b/lib/active_document/railties/controller_runtime.rb
index 5d067b459..35b765c79 100644
--- a/lib/active_document/railties/controller_runtime.rb
+++ b/lib/active_document/railties/controller_runtime.rb
@@ -6,14 +6,14 @@ module ControllerRuntime
 
       # This extension mimics the Rails' internal method to
       # measure ActiveRecord runtime during request processing.
-      # It appends MongoDB runtime value (`mongoid_runtime`) into payload
+      # It appends MongoDB runtime value (`active_document_runtime`) into payload
       # of instrumentation event `process_action.action_controller`.
       module ControllerExtension
         extend ActiveSupport::Concern
 
         protected
 
-        attr_internal :mongoid_runtime
+        attr_internal :active_document_runtime
 
         # Reset the runtime before each action.
         def process_action(action, *args)
@@ -26,14 +26,14 @@ def cleanup_view_runtime
           mongo_rt_before_render = Collector.reset_runtime
           runtime = super
           mongo_rt_after_render = Collector.reset_runtime
-          self.mongoid_runtime = mongo_rt_before_render + mongo_rt_after_render
+          self.active_document_runtime = mongo_rt_before_render + mongo_rt_after_render
           runtime - mongo_rt_after_render
         end
 
         # Add the measurement to the instrumentation event payload.
         def append_info_to_payload(payload)
           super
-          payload[:mongoid_runtime] = (mongoid_runtime || 0) + Collector.reset_runtime
+          payload[:active_document_runtime] = (active_document_runtime || 0) + Collector.reset_runtime
         end
 
         module ClassMethods
@@ -42,8 +42,8 @@ module ClassMethods
           # log message.
           def log_process_action(payload)
             messages = super
-            mongoid_runtime = payload[:mongoid_runtime]
-            messages << format('MongoDB: %.1fms', mongoid_runtime.to_f) if mongoid_runtime
+            active_document_runtime = payload[:active_document_runtime]
+            messages << format('MongoDB: %.1fms', active_document_runtime.to_f) if active_document_runtime
             messages
           end
         end
diff --git a/lib/active_document/threaded.rb b/lib/active_document/threaded.rb
index 724df3f2c..cc50d84e5 100644
--- a/lib/active_document/threaded.rb
+++ b/lib/active_document/threaded.rb
@@ -8,33 +8,33 @@ module ActiveDocument
   # on the current thread.
   module Threaded
 
-    DATABASE_OVERRIDE_KEY = '[mongoid]:db-override'
+    DATABASE_OVERRIDE_KEY = '[active_document]:db-override'
 
     # Constant for the key to store clients.
-    CLIENTS_KEY = '[mongoid]:clients'
+    CLIENTS_KEY = '[active_document]:clients'
 
     # The key to override the client.
-    CLIENT_OVERRIDE_KEY = '[mongoid]:client-override'
+    CLIENT_OVERRIDE_KEY = '[active_document]:client-override'
 
     # The key for the current thread's scope stack.
-    CURRENT_SCOPE_KEY = '[mongoid]:current-scope'
+    CURRENT_SCOPE_KEY = '[active_document]:current-scope'
 
-    AUTOSAVES_KEY = '[mongoid]:autosaves'
-    VALIDATIONS_KEY = '[mongoid]:validations'
+    AUTOSAVES_KEY = '[active_document]:autosaves'
+    VALIDATIONS_KEY = '[active_document]:validations'
 
     STACK_KEYS = Hash.new do |hash, key|
-      hash[key] = "[mongoid]:#{key}-stack"
+      hash[key] = "[active_document]:#{key}-stack"
     end
 
     # The key for the current thread's sessions.
-    SESSIONS_KEY = '[mongoid]:sessions'
+    SESSIONS_KEY = '[active_document]:sessions'
 
     # The key for storing documents modified inside transactions.
-    MODIFIED_DOCUMENTS_KEY = '[mongoid]:modified-documents'
+    MODIFIED_DOCUMENTS_KEY = '[active_document]:modified-documents'
 
     # The key storing the default value for whether or not callbacks are
     # executed on documents.
-    EXECUTE_CALLBACKS = '[mongoid]:execute-callbacks'
+    EXECUTE_CALLBACKS = '[active_document]:execute-callbacks'
 
     extend self
 
diff --git a/lib/active_document/timestamps/timeless.rb b/lib/active_document/timestamps/timeless.rb
index 606fdce95..ae4b2c8de 100644
--- a/lib/active_document/timestamps/timeless.rb
+++ b/lib/active_document/timestamps/timeless.rb
@@ -52,7 +52,7 @@ class << self
         #
         # @api private
         def timeless_table
-          Thread.current['[mongoid]:timeless'] ||= {}
+          Thread.current['[active_document]:timeless'] ||= {}
         end
 
         def_delegators :timeless_table, :[]=, :[]
diff --git a/lib/active_document/touchable.rb b/lib/active_document/touchable.rb
index 34f1b7dbf..4b2cdaddd 100644
--- a/lib/active_document/touchable.rb
+++ b/lib/active_document/touchable.rb
@@ -188,7 +188,7 @@ def touch_callbacks_suppressed?(name)
     private
 
     # The key to use to store the active touch callback suppression statuses
-    SUPPRESS_TOUCH_CALLBACKS_KEY = '[mongoid]:suppress-touch-callbacks'
+    SUPPRESS_TOUCH_CALLBACKS_KEY = '[active_document]:suppress-touch-callbacks'
 
     # Returns a hash to be used to store and query the various touch callback
     # suppression statuses for different classes.
diff --git a/lib/active_document/traversable.rb b/lib/active_document/traversable.rb
index 0da2cd93a..ff3774bce 100644
--- a/lib/active_document/traversable.rb
+++ b/lib/active_document/traversable.rb
@@ -93,7 +93,7 @@ module DiscriminatorAssignment
       def discriminator_key=(value)
         raise Errors::InvalidDiscriminatorKeyTarget.new(self, superclass) if hereditary?
 
-        _mongoid_clear_types
+        _active_document_clear_types
 
         if value
           ActiveDocument::Fields::Validators::Macro.validate_field_name(self, value)
@@ -125,7 +125,7 @@ class << self
       # @api private
       def discriminator_value=(value)
         value ||= name
-        _mongoid_clear_types
+        _active_document_clear_types
         add_discriminator_mapping(value)
         @discriminator_value = value
       end
diff --git a/lib/config/locales/en.yml b/lib/config/locales/en.yml
index c8e921c53..16a29a36f 100644
--- a/lib/config/locales/en.yml
+++ b/lib/config/locales/en.yml
@@ -116,7 +116,7 @@ en:
             mongo shell."
         empty_config_file:
           message: "Empty configuration file: %{path}."
-          summary: "Your activedocument.yml configuration file appears to be empty."
+          summary: "Your active_document.yml configuration file appears to be empty."
           resolution: "Ensure your configuration file contains the correct contents.
             Refer to: https://www.mongodb.com/docs/mongoid/current/reference/configuration/"
         gem_conflict:
@@ -173,14 +173,14 @@ en:
             \_\_https://www.mongodb.com/docs/ruby-driver/current/reference/client-side-encryption/#auto-encryption-options"
         invalid_config_file:
           message: "Invalid configuration file: %{path}."
-          summary: "Your activedocument.yml configuration file does not contain the
+          summary: "Your active_document.yml configuration file does not contain the
             correct file structure."
           resolution: "Ensure your configuration file contains the correct contents.
             Refer to: https://www.mongodb.com/docs/mongoid/current/reference/configuration/"
         invalid_config_option:
           message: "Invalid configuration option: %{name}."
           summary: "A invalid configuration option was provided in your
-            activedocument.yml, or a typo is potentially present. The valid configuration
+            active_document.yml, or a typo is potentially present. The valid configuration
             options are: %{options}."
           resolution: "Remove the invalid option or fix the typo. If you were
             expecting the option to be there, please consult the following page
@@ -492,7 +492,7 @@ en:
           message: "No default client configuration is defined."
           summary: "The configuration provided settings for: %{keys}, but
             ActiveDocument requires a :default to be defined at minimum."
-          resolution: "If configuring via a activedocument.yml, ensure that within
+          resolution: "If configuring via a active_document.yml, ensure that within
             your :clients section a :default client is defined.\n\n
             Example:\n
             \_\_development:\n
@@ -563,7 +563,7 @@ en:
             not find a client configuration for the name: '%{name}'. This is
             necessary in order to know the host, port, and options needed
             to connect."
-          resolution: "Double check your activedocument.yml to make sure under the
+          resolution: "Double check your active_document.yml to make sure under the
             clients key that a configuration exists for '%{name}'. If you
             have set the configuration programmatically, ensure that '%{name}'
             exists in the configuration hash."
@@ -572,9 +572,9 @@ en:
           summary: "ActiveDocument's configuration requires that you provide details
             about each client that can be connected to, and requires in
             the clients config at least 1 default client to exist."
-          resolution: "Double check your activedocument.yml to make sure that you
+          resolution: "Double check your active_document.yml to make sure that you
             have a top-level clients key with at least 1 default client
-            configuration for it. You can regenerate a new activedocument.yml for
+            configuration for it. You can regenerate a new active_document.yml for
             assistance via `rails g mongoid:config`.\n\n
             Example:\n
             \_\_development:\n
@@ -588,7 +588,7 @@ en:
           summary: "Each client configuration must provide a database so ActiveDocument
             knows where the default database to persist to. What was provided
             was: %{config}."
-          resolution: "If configuring via a activedocument.yml, ensure that within
+          resolution: "If configuring via a active_document.yml, ensure that within
             your :%{name} section a :database value for the client's default
             database is defined.\n\n
             Example:\n
@@ -603,7 +603,7 @@ en:
           summary: "Each client configuration must provide hosts so ActiveDocument
             knows where the database server is located. What was provided
             was: %{config}."
-          resolution: "If configuring via a activedocument.yml, ensure that within
+          resolution: "If configuring via a active_document.yml, ensure that within
             your :%{name} section a :hosts value for the client hosts is
             defined.\n\n
             Example:\n
diff --git a/lib/rails/generators/active_document/config/config_generator.rb b/lib/rails/generators/active_document/config/config_generator.rb
index 296f9ad83..f9b829c56 100644
--- a/lib/rails/generators/active_document/config/config_generator.rb
+++ b/lib/rails/generators/active_document/config/config_generator.rb
@@ -32,14 +32,14 @@ def app_name # :nodoc:
         parent.underscore
       end
 
-      # Creates a +activedocument.yml+ config file from a template.
+      # Creates a +active_document.yml+ config file from a template.
       def create_config_file
-        template 'activedocument.yml', File.join('config', 'activedocument.yml')
+        template 'active_document.yml', File.join('config', 'active_document.yml')
       end
 
       # Creates a +active_document.rb+ initializer file from a template.
       def create_initializer_file
-        template 'mongoid.rb', File.join('config', 'initializers', 'mongoid.rb')
+        template 'active_document.rb', File.join('config', 'initializers', 'active_document.rb')
       end
     end
   end
diff --git a/lib/rails/generators/active_document/config/templates/mongoid.rb b/lib/rails/generators/active_document/config/templates/mongoid.rb
index 479e1110b..0c181d440 100644
--- a/lib/rails/generators/active_document/config/templates/mongoid.rb
+++ b/lib/rails/generators/active_document/config/templates/mongoid.rb
@@ -7,13 +7,13 @@
   # features flags (refer to documentation)
   config.load_defaults target_version
 
-  # It is recommended to use config/activedocument.yml for most ActiveDocument-related
+  # It is recommended to use config/active_document.yml for most ActiveDocument-related
   # configuration, whenever possible, but if you prefer, you can set
   # configuration values here, instead:
   #
   #   config.log_level = :debug
   #
-  # Note that the settings in config/activedocument.yml always take precedence,
+  # Note that the settings in config/active_document.yml always take precedence,
   # whatever else is set here.
 end
 
diff --git a/perf/benchmark.rb b/perf/benchmark.rb
index d0312c311..ca73a67d0 100644
--- a/perf/benchmark.rb
+++ b/perf/benchmark.rb
@@ -4,7 +4,7 @@
 require "active_document"
 require "./perf/models"
 
-ActiveDocument.connect_to("mongoid_perf_test")
+ActiveDocument.connect_to("active_document_perf_test")
 Mongo::Logger.logger.level = ::Logger::FATAL
 
 ActiveDocument.purge!
diff --git a/perf/benchmark_ips.rb b/perf/benchmark_ips.rb
index ef5329d6f..b2ef93f50 100644
--- a/perf/benchmark_ips.rb
+++ b/perf/benchmark_ips.rb
@@ -2,18 +2,18 @@
 
 require "benchmark/ips"
 require "active_document"
-require "./perf/models"
+require './perf/models'
 require './perf/gc_suite'
 
-ActiveDocument.connect_to("mongoid_perf_test")
+ActiveDocument.connect_to('active_document_perf_test')
 Mongo::Logger.logger.level = ::Logger::FATAL
 ActiveDocument.purge!
 
-puts "Creating indexes..."
+puts 'Creating indexes...'
 
 [ Person, Post, Game, Preference ].each(&:create_indexes)
 
-puts "Starting benchmark..."
+puts 'Starting benchmark...'
 
 suite = GCSuite.new
 
diff --git a/perf/benchmark_ips_iteration_cases.rb b/perf/benchmark_ips_iteration_cases.rb
index ce623587c..8e75dc420 100644
--- a/perf/benchmark_ips_iteration_cases.rb
+++ b/perf/benchmark_ips_iteration_cases.rb
@@ -2,10 +2,10 @@
 
 require "benchmark/ips"
 require "active_document"
-require "./perf/models"
+require './perf/models'
 require './perf/gc_suite'
 
-ActiveDocument.connect_to("mongoid_perf_test")
+ActiveDocument.connect_to('active_document_perf_test')
 Mongo::Logger.logger.level = ::Logger::FATAL
 ActiveDocument.purge!
 
diff --git a/perf/profile.rb b/perf/profile.rb
index 826c6beaa..2c1b4e06e 100644
--- a/perf/profile.rb
+++ b/perf/profile.rb
@@ -4,7 +4,7 @@
 require "active_document"
 require "./perf/models"
 
-ActiveDocument.connect_to("mongoid_perf_test")
+ActiveDocument.connect_to("active_document_perf_test")
 
 ActiveDocument.purge!
 
diff --git a/spec/active_document/clients_spec.rb b/spec/active_document/clients_spec.rb
index 8a44cc0ab..e50107124 100644
--- a/spec/active_document/clients_spec.rb
+++ b/spec/active_document/clients_spec.rb
@@ -544,7 +544,7 @@
   describe '#mongo_client' do
 
     let(:file) do
-      File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+      File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
     end
 
     before do
@@ -556,7 +556,7 @@
     context 'when getting the default' do
 
       let(:file) do
-        File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+        File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
       end
       let!(:band) do
         Band.new
@@ -656,7 +656,7 @@
   describe '.mongo_client' do
 
     let(:file) do
-      File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+      File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
     end
 
     before do
@@ -672,7 +672,7 @@
     context 'when getting the default' do
 
       let(:file) do
-        File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+        File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
       end
       let!(:mongo_client) do
         Band.mongo_client
@@ -1160,7 +1160,7 @@ class StoreChild2 < StoreParent
   context 'when overriding the default database' do
 
     let(:file) do
-      File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+      File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
     end
 
     before do
diff --git a/spec/active_document/config/environment_spec.rb b/spec/active_document/config/environment_spec.rb
index 66a9b8244..dd487b790 100644
--- a/spec/active_document/config/environment_spec.rb
+++ b/spec/active_document/config/environment_spec.rb
@@ -61,7 +61,7 @@
   describe '#load_yaml' do
     subject { described_class.load_yaml(path, environment) }
 
-    let(:path) { 'activedocument.yml' }
+    let(:path) { 'active_document.yml' }
     let(:environment) {}
 
     before do
@@ -77,7 +77,7 @@
 
     context 'when file found' do
       before do
-        allow(File).to receive(:read).with('activedocument.yml').and_return(file_contents)
+        allow(File).to receive(:read).with('active_document.yml').and_return(file_contents)
       end
 
       let(:file_contents) do
@@ -140,7 +140,7 @@
       raise 'Expected to find some schema maps' if paths.empty?
 
       before do
-        allow(File).to receive(:read).with('activedocument.yml').and_return(file_contents)
+        allow(File).to receive(:read).with('active_document.yml').and_return(file_contents)
       end
 
       let(:file_contents) do
diff --git a/spec/active_document/config_spec.rb b/spec/active_document/config_spec.rb
index 88394f4d1..9e18bd3ad 100644
--- a/spec/active_document/config_spec.rb
+++ b/spec/active_document/config_spec.rb
@@ -337,7 +337,7 @@
   describe '#load!' do
 
     let(:file) do
-      File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+      File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
     end
 
     context 'when existing clients exist in the configuration' do
diff --git a/spec/active_document/errors/invalid_config_file_spec.rb b/spec/active_document/errors/invalid_config_file_spec.rb
index 0cdabc1b6..c82dfec14 100644
--- a/spec/active_document/errors/invalid_config_file_spec.rb
+++ b/spec/active_document/errors/invalid_config_file_spec.rb
@@ -18,7 +18,7 @@
 
     it 'contains the summary in the message' do
       expect(error.message).to include(
-        'Your activedocument.yml configuration file does not contain the'
+        'Your active_document.yml configuration file does not contain the'
       )
     end
 
diff --git a/spec/active_document/errors/invalid_config_option_spec.rb b/spec/active_document/errors/invalid_config_option_spec.rb
index 5c731a89d..8b63226b3 100644
--- a/spec/active_document/errors/invalid_config_option_spec.rb
+++ b/spec/active_document/errors/invalid_config_option_spec.rb
@@ -18,7 +18,7 @@
 
     it 'contains the summary in the message' do
       expect(error.message).to include(
-        'A invalid configuration option was provided in your activedocument.yml,'
+        'A invalid configuration option was provided in your active_document.yml,'
       )
     end
 
diff --git a/spec/active_document/errors/no_client_config_spec.rb b/spec/active_document/errors/no_client_config_spec.rb
index 53ca2c6fc..e47026c31 100644
--- a/spec/active_document/errors/no_client_config_spec.rb
+++ b/spec/active_document/errors/no_client_config_spec.rb
@@ -24,7 +24,7 @@
 
     it 'contains the resolution in the message' do
       expect(error.message).to include(
-        'Double check your activedocument.yml to make sure under the clients'
+        'Double check your active_document.yml to make sure under the clients'
       )
     end
   end
diff --git a/spec/active_document/errors/no_client_database_spec.rb b/spec/active_document/errors/no_client_database_spec.rb
index 4848a1402..49d384653 100644
--- a/spec/active_document/errors/no_client_database_spec.rb
+++ b/spec/active_document/errors/no_client_database_spec.rb
@@ -24,7 +24,7 @@
 
     it 'contains the resolution in the message' do
       expect(error.message).to include(
-        'If configuring via a activedocument.yml, ensure that within your :analytics'
+        'If configuring via a active_document.yml, ensure that within your :analytics'
       )
     end
   end
diff --git a/spec/active_document/errors/no_client_hosts_spec.rb b/spec/active_document/errors/no_client_hosts_spec.rb
index 67db4b1b4..2f83cae23 100644
--- a/spec/active_document/errors/no_client_hosts_spec.rb
+++ b/spec/active_document/errors/no_client_hosts_spec.rb
@@ -24,7 +24,7 @@
 
     it 'contains the resolution in the message' do
       expect(error.message).to include(
-        'If configuring via a activedocument.yml, ensure that within your :analytics'
+        'If configuring via a active_document.yml, ensure that within your :analytics'
       )
     end
   end
diff --git a/spec/active_document/errors/no_clients_config_spec.rb b/spec/active_document/errors/no_clients_config_spec.rb
index 7bc0b3dd0..68bc7a1f8 100644
--- a/spec/active_document/errors/no_clients_config_spec.rb
+++ b/spec/active_document/errors/no_clients_config_spec.rb
@@ -24,7 +24,7 @@
 
     it 'contains the resolution in the message' do
       expect(error.message).to include(
-        'Double check your activedocument.yml to make sure that you have'
+        'Double check your active_document.yml to make sure that you have'
       )
     end
   end
diff --git a/spec/active_document/persistence_context_spec.rb b/spec/active_document/persistence_context_spec.rb
index 1b4f313e3..158fe98b1 100644
--- a/spec/active_document/persistence_context_spec.rb
+++ b/spec/active_document/persistence_context_spec.rb
@@ -261,7 +261,7 @@
       context 'when the parent object has a client set' do
 
         let(:file) do
-          File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+          File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
         end
 
         before do
diff --git a/spec/integration/app_spec.rb b/spec/integration/app_spec.rb
index 0b3915266..3732a55df 100644
--- a/spec/integration/app_spec.rb
+++ b/spec/integration/app_spec.rb
@@ -136,7 +136,7 @@ def prepare_new_rails_app(name)
 
     it 'generates ActiveDocument config' do
       prepare_new_rails_app 'active_document-test-config' do
-        active_document_config_file = File.join(TMP_BASE, 'active_document-test-config/config/activedocument.yml')
+        active_document_config_file = File.join(TMP_BASE, 'active_document-test-config/config/active_document.yml')
 
         expect(File.exist?(active_document_config_file)).to be false
         check_call(%w[rails g active_document:config], env: clean_env)
@@ -287,7 +287,7 @@ def write_active_document_yml
       'uri' => uri
     } } }
     config = { 'development' => env_config, 'production' => env_config }
-    File.open('config/activedocument.yml', 'w') do |f|
+    File.open('config/active_document.yml', 'w') do |f|
       f << YAML.dump(config)
     end
   end
diff --git a/spec/support/macros.rb b/spec/support/macros.rb
index a5b8dd5e3..ff35846d8 100644
--- a/spec/support/macros.rb
+++ b/spec/support/macros.rb
@@ -5,7 +5,7 @@ module Macros
 
     def use_spec_active_document_config
       around do |example|
-        config_path = File.join(File.dirname(__FILE__), '..', 'config', 'activedocument.yml')
+        config_path = File.join(File.dirname(__FILE__), '..', 'config', 'active_document.yml')
 
         ActiveDocument::Clients.clear
         ActiveDocument.load!(config_path, :test)