diff --git a/src/renderers/WebGLRenderer.js b/src/renderers/WebGLRenderer.js
index 093d1a42b2e21bb2c0c07bf5cb61e4306b0d6639..833ee152903866e5f798eda7a5b9873a88bd14d8 100644
--- a/src/renderers/WebGLRenderer.js
+++ b/src/renderers/WebGLRenderer.js
@@ -4689,7 +4689,7 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 					addBuffer( scene.__webglObjects, geometry, object );
 
-				} else {
+				} else if ( geometry instanceof THREE.Geometry ) {
 
 					for ( g in geometry.geometryGroups ) {