Corrects logconfig from #2956
diff --git a/src/ruby/lib/grpc/logconfig.rb b/src/ruby/lib/grpc/logconfig.rb
index 2bb7c86..6b442fe 100644
--- a/src/ruby/lib/grpc/logconfig.rb
+++ b/src/ruby/lib/grpc/logconfig.rb
@@ -54,5 +54,6 @@
     LOGGER = NoopLogger.new
   end
 
-  include DefaultLogger unless method_defined?(:logger)
+  # Inject the noop #logger if no module-level logger method has been injected.
+  extend DefaultLogger unless methods.include?(:logger)
 end