diff --git a/CHANGELOG.md b/CHANGELOG.md
index dcfa649..909ed5f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.1.1
+
+Add `.formatter.exs` file to release for `import_deps`
+
 ## 0.1.0
 
 Pre-release, this is not a production ready release !
diff --git a/README.md b/README.md
index 165d881..8d367d8 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,7 @@ The package can be installed by adding `elvengard_network` to your list of depen
 ```elixir
 def deps do
   [
-    {:elvengard_network, "~> 0.1.0"}
+    {:elvengard_network, "~> 0.1.1"}
   ]
 end
 ```
diff --git a/guides/introduction/getting_started.md b/guides/introduction/getting_started.md
index 567de1a..8eaea15 100644
--- a/guides/introduction/getting_started.md
+++ b/guides/introduction/getting_started.md
@@ -21,7 +21,7 @@ To add ElvenGard.Network to this application, just add an entry to your mix.exs:
 ```elixir
 defp deps do
   [
-    {:elvengard_network, "~> 0.1.0"}
+    {:elvengard_network, "~> 0.1.1"}
   ]
 end
 ```
diff --git a/lib/elven_gard/network/packet_serializer.ex b/lib/elven_gard/network/packet_serializer.ex
index ec3ef22..78fd17b 100644
--- a/lib/elven_gard/network/packet_serializer.ex
+++ b/lib/elven_gard/network/packet_serializer.ex
@@ -221,17 +221,32 @@ defmodule ElvenGard.Network.PacketSerializer do
   defp def_serialize(%{id: id, fields: fields}) do
     fields_ast =
       Enum.map(fields, fn %{name: name, type: type, opts: opts} ->
-        quote location: :keep do
-          case {Map.fetch!(var!(packet), unquote(name)), opts[:default]} do
-            {nil, value} when not is_nil(value) -> value
-            {value, _} -> unquote(type).encode(value, unquote(opts))
-          end
+        case Keyword.get(opts, :if) do
+          nil ->
+            quote location: :keep do
+              case {Map.fetch!(var!(packet), unquote(name)), opts[:default]} do
+                {nil, value} when not is_nil(value) -> value
+                {value, _} -> unquote(type).encode(value, unquote(opts))
+              end
+            end
+
+          condition ->
+            quote location: :keep do
+              if unquote(condition) in [nil, false] do
+                :"$drop"
+              else
+                case {Map.fetch!(var!(packet), unquote(name)), opts[:default]} do
+                  {nil, value} when not is_nil(value) -> value
+                  {value, _} -> unquote(type).encode(value, unquote(opts))
+                end
+              end
+            end
         end
       end)
 
     quote location: :keep, generated: true do
       def serialize(%__MODULE__{} = var!(packet)) do
-        {unquote(id), unquote(fields_ast)}
+        {unquote(id), Enum.reject(unquote(fields_ast), &match?(:"$drop", &1))}
       end
     end
   end
diff --git a/mix.exs b/mix.exs
index 68b40b5..7c38762 100644
--- a/mix.exs
+++ b/mix.exs
@@ -2,7 +2,7 @@ defmodule ElvenGard.Network.MixProject do
   use Mix.Project
 
   @app_name "ElvenGard.Network"
-  @version "0.1.0"
+  @version "0.1.1"
   @github_link "https://github.com/ImNotAVirus/elvengard_network"
 
   def project do
@@ -51,7 +51,7 @@ defmodule ElvenGard.Network.MixProject do
       maintainers: ["ImNotAVirus"],
       licenses: ["MIT"],
       links: %{"GitHub" => @github_link},
-      files: ~w(lib CHANGELOG.md LICENSE.md mix.exs README.md)
+      files: ~w(lib CHANGELOG.md LICENSE.md mix.exs .formatter.exs README.md)
     ]
   end