diff --git a/lib/ex_type/custom_env.ex b/lib/ex_type/custom_env.ex
index d1459a3..f5de351 100644
--- a/lib/ex_type/custom_env.ex
+++ b/lib/ex_type/custom_env.ex
@@ -111,6 +111,13 @@ defmodule ExType.CustomEnv do
 
     new_alias = {:__aliases__, meta, new_alias_prefix ++ tokens}
 
+    # Manually expand `alias __MODULE__`, see https://github.com/gyson/ex_type/issues/27
+    block = block
+      |> Macro.prewalk(fn
+          {:alias, meta_alias, [{:__MODULE__, meta_module, nil}]} -> {:alias, meta_alias, [{:__aliases__, meta_module, tokens}]}
+          token -> token
+        end)
+
     quote do
       Kernel.defmodule unquote(new_alias) do
         @before_compile ExType.CustomEnv.BeforeCompile