3 files changed, 15 insertions, 0 deletions
diff --git a/activesupport/test/autoloading_fixtures/prepend.rb b/activesupport/test/autoloading_fixtures/prepend.rb
new file mode 100644
index 0000000000..3134d1df2b
--- /dev/null
+++ b/activesupport/test/autoloading_fixtures/prepend.rb
@@ -0,0 +1,8 @@
+class SubClassConflict
+end
+
+class Prepend
+  module PrependedModule
+  end
+  prepend PrependedModule
+end
diff --git a/activesupport/test/autoloading_fixtures/prepend/sub_class_conflict.rb b/activesupport/test/autoloading_fixtures/prepend/sub_class_conflict.rb
new file mode 100644
index 0000000000..090dda3043
--- /dev/null
+++ b/activesupport/test/autoloading_fixtures/prepend/sub_class_conflict.rb
@@ -0,0 +1,2 @@
+class Prepend::SubClassConflict
+end
diff --git a/activesupport/test/constantize_test_cases.rb b/activesupport/test/constantize_test_cases.rb
index af2db8c991..32b720bcbb 100644
--- a/activesupport/test/constantize_test_cases.rb
+++ b/activesupport/test/constantize_test_cases.rb
@@ -73,6 +73,11 @@ module ConstantizeTestCases
         yield("RaisesNoMethodError")
       end
     end
+
+    with_autoloading_fixtures do
+      yield("Prepend::SubClassConflict")
+      assert_equal "constant", defined?(Prepend::SubClassConflict)
+    end
   end
 
   def run_safe_constantize_tests_on