1 files changed, 7 insertions, 0 deletions
diff --git a/test/ruby/test_marshal.rb b/test/ruby/test_marshal.rb
index 3d5d6c9b1f..c8d79edb02 100644
--- a/test/ruby/test_marshal.rb
+++ b/test/ruby/test_marshal.rb
@@ -647,4 +647,11 @@ class TestMarshal < Test::Unit::TestCase
       c.cc.call
     end
   end
+
+  def test_undumpable_message
+    c = Module.new {break module_eval("class IO\u{26a1} < IO;self;end")}
+    assert_raise_with_message(TypeError, /IO\u{26a1}/) {
+      Marshal.dump(c.new(0, autoclose: false))
+    }
+  end
 end