diff --git a/src/builder.py b/src/builder.py
index a255963..908bf61 100644
--- a/src/builder.py
+++ b/src/builder.py
@@ -80,7 +80,7 @@ class ASEBuilder(object):
                     material_indices.append(material_index)
 
             mesh_data.calc_loop_triangles()
-            mesh_data.calc_normals_split()
+            
             poly_groups, groups = mesh_data.calc_smooth_groups(use_bitflags=False)
 
             # Faces