diff --git a/io_scene_obj/__init__.py b/io_scene_obj/__init__.py
index 6d1312ec7f08b7ce7553cd665dcf15241a72789b..6e854b9e75b366c721f7a006a3381f9c31505ea6 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, 3),
+    "version": (2, 3, 4),
     "blender": (2, 77, 0),
     "location": "File > Import-Export",
     "description": "Import-Export OBJ, Import OBJ mesh, UV's, materials and textures",
diff --git a/io_scene_obj/export_obj.py b/io_scene_obj/export_obj.py
index 89613368688cca90292db4bc89bd20c0dca0694f..e28d607dd69f37a16610d8925f391c95b4f827f7 100644
--- a/io_scene_obj/export_obj.py
+++ b/io_scene_obj/export_obj.py
@@ -397,6 +397,9 @@ def write_file(filepath, objects, scene,
                             continue
 
                         me.transform(EXPORT_GLOBAL_MATRIX * ob_mat)
+                        # If negative scaling, we have to invert the normals...
+                        if ob_mat.determinant() < 0.0:
+                            me.flip_normals()
 
                         if EXPORT_TRI:
                             # _must_ do this first since it re-allocs arrays