diff --git a/setup_main_tex_file.py b/setup_main_tex_file.py
index 35d2381..2e9f737 100755
--- a/setup_main_tex_file.py
+++ b/setup_main_tex_file.py
@@ -438,7 +438,10 @@ def main():
         parser_compile.set_defaults(func=tex_compile)
 
     args = parser.parse_args()
-    args.func(args)
+    if hasattr(args, 'func'):
+        args.func(args)
+    else:
+        parser.print_usage()
     
                             
 class Outline: