diff --git a/lib/obj.js b/lib/obj.js
index 6e8a362..b60e569 100644
--- a/lib/obj.js
+++ b/lib/obj.js
@@ -291,13 +291,11 @@ function getImages(inputPath, materials) {
 }
 
 function getMaterials(mtlPath, hasMaterialGroups) {
-    if (!hasMaterialGroups) {
-        return;
-    }
-
-    if (defined(mtlPath)) {
+    if (hasMaterialGroups && defined(mtlPath)) {
         return Material.parse(mtlPath);
     }
+
+    return {};
 }
 
 function getObjInfo(objFile, inputPath) {