diff --git a/generator/generator.py b/generator/generator.py
index 27fb0c7..4a79de1 100755
--- a/generator/generator.py
+++ b/generator/generator.py
@@ -28,7 +28,7 @@ for dir_name, _, filenames in os.walk(cur_path):
  
     output_filename = filename.replace('.dbc', '_generated.dbc')
 
-    with open(os.path.join(generator_path, output_filename), 'a') as dbc_file_out:
+    with open(os.path.join(generator_path, output_filename), 'w') as dbc_file_out:
       dbc_file_out.write('CM_ "AUTOGENERATED FILE, DO NOT EDIT"\n')
 
       for include_filename in reversed(includes):