diff --git a/ifstools.py b/ifstools.py
index d7b94e9..5bce975 100644
--- a/ifstools.py
+++ b/ifstools.py
@@ -84,5 +84,5 @@ if __name__ == '__main__':
     if len(sys.argv) < 2:
         print('ifstools filename.ifs')
         exit()
-    i = IFS(argv[1])
+    i = IFS(sys.argv[1])
     i.extract_all()