diff --git a/test/integration/drop_test.rb b/test/integration/drop_test.rb
index 01484b9..6069713 100644
--- a/test/integration/drop_test.rb
+++ b/test/integration/drop_test.rb
@@ -33,7 +33,7 @@ class ProductDrop < Liquid::Drop
 
   class CatchallDrop < Liquid::Drop
     def liquid_method_missing(method)
-      +'catchall_method: ' << method.to_s
+      "catchall_method: #{method}"
     end
   end