diff --git a/src/extras/geometries/BoxGeometry.js b/src/extras/geometries/BoxGeometry.js
index 0442c098d9dfaafc1884f48c3e595424930e5aba..2f667c52f717e73719436a51713dda3806645d08 100644
--- a/src/extras/geometries/BoxGeometry.js
+++ b/src/extras/geometries/BoxGeometry.js
@@ -20,6 +20,7 @@ THREE.BoxGeometry = function ( width, height, depth, widthSegments, heightSegmen
 
 	this.fromBufferGeometry( new THREE.BoxBufferGeometry( width, height, depth, widthSegments, heightSegments, depthSegments ) );
 
+	this.mergeVertices();
 };
 
 THREE.BoxGeometry.prototype = Object.create( THREE.Geometry.prototype );