diff --git a/packages/testkit-backend/src/feature/common.js b/packages/testkit-backend/src/feature/common.js
index 756bcc92a..ac0bb266d 100644
--- a/packages/testkit-backend/src/feature/common.js
+++ b/packages/testkit-backend/src/feature/common.js
@@ -44,7 +44,8 @@ const features = [
   'Optimization:ImplicitDefaultArguments',
   'Optimization:MinimalBookmarksSet',
   'Optimization:MinimalResets',
-  'Optimization:AuthPipelining'
+  'Optimization:AuthPipelining',
+  'Detail:NumberIsNumber'
 ]
 
 export default features