diff --git a/helper/diffPlaces.js b/helper/diffPlaces.js
index 840f02033..d11ef0ba3 100644
--- a/helper/diffPlaces.js
+++ b/helper/diffPlaces.js
@@ -168,6 +168,9 @@ const parentGID = (item, layer) => {
  */
 function isEquivalentIdentity(item1, item2) {
 
+  // Both items must be on the same layer
+  if (item1.layer !== item2.layer) { return false; }
+
   // Generate a GID value for each item
   const gid1 = GID(item1);
   const gid2 = GID(item2);