diff --git a/.travis.yml b/.travis.yml
index 542c79c..a68712b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,10 @@ sudo: false
 
 matrix:
   include:
+  - elixir: 1.9.1
+    otp_release: 22.0.7
+  - elixir: 1.8.2
+    otp_release: 21.3.8
   - elixir: 1.7.2
     otp_release: 21.0
   - elixir: 1.7.2
diff --git a/lib/construct.ex b/lib/construct.ex
index 7a4809a..7e08c41 100644
--- a/lib/construct.ex
+++ b/lib/construct.ex
@@ -30,6 +30,9 @@ defmodule Construct do
   @type_checker_name Construct.TypeRegistry
   @no_default :__construct_no_default__
 
+  # elixir 1.9.0 do not raise deadlocks for Code.ensure_compiled/1
+  @no_raise_on_deadlocks Version.compare(System.version(), "1.9.0") != :lt
+
   @doc false
   defmacro __using__(opts \\ [])
 
@@ -117,11 +120,11 @@ defmodule Construct do
       module = unquote(struct)
 
       unless Code.ensure_compiled?(module) do
-        raise Construct.DefinitionError, "undefined module #{module}"
+        raise Construct.DefinitionError, "undefined module #{inspect(module)}"
       end
 
       unless function_exported?(module, :__construct__, 1) do
-        raise Construct.DefinitionError, "provided #{module} is not Construct module"
+        raise Construct.DefinitionError, "provided #{inspect(module)} is not Construct module"
       end
 
       Enum.each(module.__construct__(:types), fn({name, {type, opts}}) ->
@@ -354,13 +357,15 @@ defmodule Construct do
   end
 
   defp check_type_complex!(module) do
+    if @no_raise_on_deadlocks, do: Code.ensure_compiled(module)
+
     unless construct_module?(module) do
       unless Code.ensure_compiled?(module) do
-        raise Construct.DefinitionError, "undefined module #{module}"
+        raise Construct.DefinitionError, "undefined module #{inspect(module)}"
       end
 
       unless function_exported?(module, :cast, 1) do
-        raise Construct.DefinitionError, "undefined function cast/1 for #{module}"
+        raise Construct.DefinitionError, "undefined function cast/1 for #{inspect(module)}"
       end
     end
   end
@@ -407,8 +412,6 @@ defmodule Construct do
   end
 
   defp construct_module?(module) do
-    Code.ensure_compiled(module)
-
     Agent.get(@type_checker_name, &MapSet.member?(&1, module)) ||
       Code.ensure_compiled?(module) && function_exported?(module, :__construct__, 1)
   end
diff --git a/test/integration/build_test.exs b/test/integration/build_test.exs
index 352cf93..317d44e 100644
--- a/test/integration/build_test.exs
+++ b/test/integration/build_test.exs
@@ -120,19 +120,19 @@ defmodule Construct.Integration.BuildTest do
   end
 
   test "raise when trying to use undefined module as custom type" do
-    assert_raise(Construct.DefinitionError, ~s(undefined module Elixir.UndefinedModule), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined module UndefinedModule), fn ->
       create_construct do
         field :key, UndefinedModule
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined module Elixir.UndefinedModule), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined module UndefinedModule), fn ->
       create_construct do
         field :key, {:array, UndefinedModule}
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined module Elixir.UndefinedModule), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined module UndefinedModule), fn ->
       create_construct do
         field :key, {:map, UndefinedModule}
       end
@@ -144,13 +144,13 @@ defmodule Construct.Integration.BuildTest do
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined module Elixir.UndefinedModule), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined module UndefinedModule), fn ->
       create_construct do
         field :key, [UndefinedModule]
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined module Elixir.UndefinedModule), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined module UndefinedModule), fn ->
       create_construct do
         field :key, [CustomType, UndefinedModule]
       end
@@ -158,19 +158,19 @@ defmodule Construct.Integration.BuildTest do
   end
 
   test "raise when trying to use custom type that doesn't have cast/1 function" do
-    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for Elixir.CustomTypeEmpty), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for CustomTypeEmpty), fn ->
       create_construct do
         field :key, CustomTypeEmpty
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for Elixir.CustomTypeEmpty), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for CustomTypeEmpty), fn ->
       create_construct do
         field :key, {:array, CustomTypeEmpty}
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for Elixir.CustomTypeEmpty), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for CustomTypeEmpty), fn ->
       create_construct do
         field :key, {:map, CustomTypeEmpty}
       end
@@ -182,13 +182,13 @@ defmodule Construct.Integration.BuildTest do
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for Elixir.CustomTypeEmpty), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for CustomTypeEmpty), fn ->
       create_construct do
         field :key, [CustomTypeEmpty]
       end
     end)
 
-    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for Elixir.CustomTypeEmpty), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined function cast/1 for CustomTypeEmpty), fn ->
       create_construct do
         field :key, [CustomType, CustomTypeEmpty]
       end
@@ -196,7 +196,7 @@ defmodule Construct.Integration.BuildTest do
   end
 
   test "raise when trying to include undefined module" do
-    assert_raise(Construct.DefinitionError, ~s(undefined module Elixir.UndefinedModule), fn ->
+    assert_raise(Construct.DefinitionError, ~s(undefined module UndefinedModule), fn ->
       create_construct do
         include UndefinedModule
       end
@@ -204,7 +204,7 @@ defmodule Construct.Integration.BuildTest do
   end
 
   test "raise when trying to include invalid structure (some module)" do
-    assert_raise(Construct.DefinitionError, ~s(provided Elixir.CustomTypeEmpty is not Construct module), fn ->
+    assert_raise(Construct.DefinitionError, ~s(provided CustomTypeEmpty is not Construct module), fn ->
       create_construct do
         include CustomTypeEmpty
       end