diff --git a/lib/ex_oauth2_provider/config.ex b/lib/ex_oauth2_provider/config.ex
index 4368fac5..d4937a95 100644
--- a/lib/ex_oauth2_provider/config.ex
+++ b/lib/ex_oauth2_provider/config.ex
@@ -43,12 +43,18 @@ defmodule ExOauth2Provider.Config do
     do: get_oauth_struct(config, :application)
 
   defp get_oauth_struct(config, name, namespace \\ "oauth") do
-    context = Macro.camelize("#{namespace}_#{name}s")
-    module = Macro.camelize("#{namespace}_#{name}")
+    case get(config, name) do
+      nil ->
+        context = Macro.camelize("#{namespace}_#{name}s")
+        module = Macro.camelize("#{namespace}_#{name}")
 
-    config
-    |> get(name)
-    |> Kernel.||(app_module(config, context, module))
+        config
+        |> get(name)
+        |> Kernel.||(app_module(config, context, module))
+
+      module ->
+        module
+    end
   end
 
   @doc """
diff --git a/test/ex_oauth2_provider/config_test.exs b/test/ex_oauth2_provider/config_test.exs
index 06d5dd03..bf08659b 100644
--- a/test/ex_oauth2_provider/config_test.exs
+++ b/test/ex_oauth2_provider/config_test.exs
@@ -10,6 +10,33 @@ defmodule ExOauth2Provider.ConfigTest do
     end)
   end
 
+  test "application/1" do
+    assert Config.application(otp_app: :my_app) == MyApp.OauthApplications.OauthApplication
+
+    Application.delete_env(:ex_oauth2_provider, ExOauth2Provider)
+    Application.put_env(:my_app, ExOauth2Provider, application: :custom_value)
+
+    assert Config.application(otp_app: :my_app) == :custom_value
+  end
+
+  test "acess_token/1" do
+    assert Config.access_token(otp_app: :my_app) == MyApp.OauthAccessTokens.OauthAccessToken
+
+    Application.delete_env(:ex_oauth2_provider, ExOauth2Provider)
+    Application.put_env(:my_app, ExOauth2Provider, access_token: :custom_value)
+
+    assert Config.access_token(otp_app: :my_app) == :custom_value
+  end
+
+  test "acess_grant/1" do
+    assert Config.access_grant(otp_app: :my_app) == MyApp.OauthAccessGrants.OauthAccessGrant
+
+    Application.delete_env(:ex_oauth2_provider, ExOauth2Provider)
+    Application.put_env(:my_app, ExOauth2Provider, access_grant: :custom_value)
+
+    assert Config.access_grant(otp_app: :my_app) == :custom_value
+  end
+
   test "repo/1" do
     assert Config.repo(otp_app: :my_app) == Dummy.Repo