diff --git a/src/core/Object3D.js b/src/core/Object3D.js
index d9416fc70894d418a404fb19cd63db8e256d1678..7ef6e276e261e8a192ca70819a8452e8384a1f93 100644
--- a/src/core/Object3D.js
+++ b/src/core/Object3D.js
@@ -543,9 +543,11 @@ Object.assign( Object3D.prototype, EventDispatcher.prototype, {
 
 		// update children
 
-		for ( var i = 0, l = this.children.length; i < l; i ++ ) {
+		var children = this.children;
+
+		for ( var i = 0, l = children.length; i < l; i ++ ) {
 
-			this.children[ i ].updateMatrixWorld( force );
+			children[ i ].updateMatrixWorld( force );
 
 		}