diff --git a/test/lib/test/unit/assertions.rb b/test/lib/test/unit/assertions.rb
index 56f6ae5337..94248d1139 100644
--- a/test/lib/test/unit/assertions.rb
+++ b/test/lib/test/unit/assertions.rb
@@ -513,6 +513,7 @@ EOT
             RubyVM::InstructionSequence.compile(src, fname, fname, line)
           end
           assert_match(error, e.message, mesg)
+          e
         end
       end