diff --git a/lib/assets/javascripts/react_ujs_mount.js b/lib/assets/javascripts/react_ujs_mount.js
index 141ac1663..06501802e 100644
--- a/lib/assets/javascripts/react_ujs_mount.js
+++ b/lib/assets/javascripts/react_ujs_mount.js
@@ -59,8 +59,8 @@
       }
 
       // Lastly, if there is a default attribute try that
-      if (constructor && constructor.default) {
-        constructor = constructor.default;
+      if (constructor && constructor['default']) {
+        constructor = constructor['default'];
       }
 
       return constructor;