diff --git a/packages/node_modules/@node-red/editor-client/src/js/ui/common/treeList.js b/packages/node_modules/@node-red/editor-client/src/js/ui/common/treeList.js
index df9592508..7f7eba1ba 100644
--- a/packages/node_modules/@node-red/editor-client/src/js/ui/common/treeList.js
+++ b/packages/node_modules/@node-red/editor-client/src/js/ui/common/treeList.js
@@ -350,10 +350,12 @@
                 delete that._items[item.id];
                 if(item.depth === 0) {
                     for(var key in that._items) {
-                        var child = that._items[key];
-                        if(child.parent && child.parent.id === item.id) {
-                            delete that._items[key].treeList;
-                            delete that._items[key];
+                        if (that._items.hasOwnProperty(key)) {
+                            var child = that._items[key];
+                            if(child.parent && child.parent.id === item.id) {
+                                delete that._items[key].treeList;
+                                delete that._items[key];
+                            }
                         }
                     }
                     that._data = that._data.filter(function(data) { return data.id !== item.id})