1 files changed, 16 insertions, 0 deletions
diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index 361a6fe993..b0a33c8609 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -1760,4 +1760,20 @@ class TestModule < Test::Unit::TestCase
       self.#{method}
     INPUT
   end
+
+  def test_prepend_gc
+    assert_separately [], %{
+      module Foo
+      end
+      class Object
+        prepend Foo
+      end
+      GC.start     # make created T_ICLASS old (or remembered shady)
+      class Object # add methods into T_ICLASS (need WB if it is old)
+        def foo; end
+        attr_reader :bar
+      end
+      1_000_000.times{''} # cause GC
+    }
+  end
 end