diff --git a/test/rubygems/test_gem_specification.rb b/test/rubygems/test_gem_specification.rb
index c19d364c66..f4d4f6a381 100644
--- a/test/rubygems/test_gem_specification.rb
+++ b/test/rubygems/test_gem_specification.rb
@@ -1209,7 +1209,7 @@ end
   end
 
   def test_to_yaml_emits_syck_compat_yaml
-    if YAML.const_defined?(:ENGINE) && !YAML::ENGINE.syck?
+    if YAML.const_defined?(:ENGINE) && YAML::ENGINE.syck?
       yamler, YAML::ENGINE.yamler = YAML::ENGINE.yamler, 'psych'
     end
     begin