diff --git a/src/fb-stubs/GK.js b/src/fb-stubs/GK.js
index 0e9dcf97a..9c3663090 100644
--- a/src/fb-stubs/GK.js
+++ b/src/fb-stubs/GK.js
@@ -19,4 +19,8 @@ export default class GK {
     }
     return false;
   }
+
+  static serializeGKs() {
+    return JSON.stringify({});
+  }
 }