1 files changed, 16 insertions, 0 deletions
diff --git a/test/ruby/test_undef.rb b/test/ruby/test_undef.rb
index e0add7c3ab..074b92be55 100644
--- a/test/ruby/test_undef.rb
+++ b/test/ruby/test_undef.rb
@@ -35,4 +35,20 @@ class TestUndef < Test::Unit::TestCase
       end
     end
   end
+
+  def test_singleton_undef
+    klass = Class.new do
+      def foo
+        :ok
+      end
+    end
+
+    klass.new.foo
+
+    klass.new.instance_eval do
+      undef foo
+    end
+
+    klass.new.foo
+  end
 end