diff --git a/src/core/structure/tree.js b/src/core/structure/tree.js
index 839b51bec..d79ac99ef 100644
--- a/src/core/structure/tree.js
+++ b/src/core/structure/tree.js
@@ -127,9 +127,7 @@
                     continue;
                 }
                 if (temp != null) {
-                    BI.each(temp.getChildren(), function(_i, t) {
-                        queue.push(t);
-                    })
+                    queue.push(...temp.getChildren());
                 }
             }
         },