diff --git a/io_scene_obj/__init__.py b/io_scene_obj/__init__.py
index d15a6cc7a3a38a5ac45f9a1625b44d8db10590a9..3bebdecd2699a2fbc0d450f26d41c039cc6d4a13 100644
--- a/io_scene_obj/__init__.py
+++ b/io_scene_obj/__init__.py
@@ -21,7 +21,7 @@
 bl_info = {
     "name": "Wavefront OBJ format",
     "author": "Campbell Barton, Bastien Montagne",
-    "version": (2, 3, 6),
+    "version": (2, 3, 7),
     "blender": (2, 78, 0),
     "location": "File > Import-Export",
     "description": "Import-Export OBJ, Import OBJ mesh, UV's, materials and textures",
diff --git a/io_scene_obj/import_obj.py b/io_scene_obj/import_obj.py
index c4275606789cb84560f84709ae71617f26a29fde..c47e66385f961bb081e56cf6a8d3f2fe92e9fcf4 100644
--- a/io_scene_obj/import_obj.py
+++ b/io_scene_obj/import_obj.py
@@ -177,7 +177,7 @@ def create_materials(filepath, relpath,
 
         elif type == 'Bump':
             bump_mult = map_options.get(b'-bm')
-            bump_mult = float(bump_mult[0]) if (bump_mult is not None and len(bump_mult) > 1) else 1.0
+            bump_mult = float(bump_mult[0]) if (bump_mult and len(bump_mult[0]) > 1) else 1.0
 
             if use_cycles:
                 mat_wrap.normal_image_set(image)