diff --git a/actionpack/lib/abstract_controller/url_for.rb b/actionpack/lib/abstract_controller/url_for.rb
index 4a95e1f276..72d07b0927 100644
--- a/actionpack/lib/abstract_controller/url_for.rb
+++ b/actionpack/lib/abstract_controller/url_for.rb
@@ -11,7 +11,7 @@ module AbstractController
 
     def _routes
       raise "In order to use #url_for, you must include routing helpers explicitly. " \
-            "For instance, `include Rails.application.routes.url_helpers"
+            "For instance, `include Rails.application.routes.url_helpers`."
     end
 
     module ClassMethods