1 files changed, 14 insertions, 0 deletions
diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index f674783a01..dd1c9bcd89 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -1623,6 +1623,20 @@ class TestRefinement < Test::Unit::TestCase
     end
   end
 
+  def test_refine_with_prepend
+    assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+      bug = '[ruby-core:78073] [Bug #12920]'
+      Fixnum.prepend(Module.new)
+      Module.new do
+        refine Fixnum do
+          define_method(:+) {}
+        end
+      end
+      assert_kind_of(Time, Time.now, bug)
+    end;
+  end
+
   private
 
   def eval_using(mod, s)