diff --git a/wfobj.py b/wfobj.py
index 5a80ff5..e0471a9 100755
--- a/wfobj.py
+++ b/wfobj.py
@@ -76,8 +76,9 @@ class WFObj(object):
                     add_face(*parts[1:])
                 elif len(parts[1:]) == 4:
                     # split the quad into two triangles
-                    add_face(*parts[1:3])
+                    add_face(*parts[1:4])
                     add_face(parts[1], parts[3], parts[4])
+                    pass
                 else:
                     raise ValueError('Faces can only have 3 or 4 vertices on line %d' % lineno)
             elif parts[0] == 'mtllib':