diff --git a/test/rubygems/test_gem_gem_runner.rb b/test/rubygems/test_gem_gem_runner.rb
index c4917b0588..81e191edb0 100644
--- a/test/rubygems/test_gem_gem_runner.rb
+++ b/test/rubygems/test_gem_gem_runner.rb
@@ -76,7 +76,7 @@ class TestGemGemRunner < Gem::TestCase
       assert_nil @runner.run(args)
     end
 
-    assert_match /WARNING:  query command is deprecated. It will be removed in Rubygems [0-9]+/, @ui.error
+    assert_match(/WARNING:  query command is deprecated. It will be removed in Rubygems [0-9]+/, @ui.error)
   end
 
   def test_info_succeeds