diff --git a/test/rubygems/test_gem_ext_cargo_builder.rb b/test/rubygems/test_gem_ext_cargo_builder.rb
index df50150d50..3230ff3f21 100644
--- a/test/rubygems/test_gem_ext_cargo_builder.rb
+++ b/test/rubygems/test_gem_ext_cargo_builder.rb
@@ -87,7 +87,7 @@ class TestGemExtCargoBuilder < Gem::TestCase
       end
     end
 
-    assert_match /cargo\s.*\sfailed/, error.message
+    assert_match(/cargo\s.*\sfailed/, error.message)
   end
 
   def test_full_integration