diff --git a/sw/pc/primer.py b/sw/pc/primer.py
index 67d1da1..e2be968 100644
--- a/sw/pc/primer.py
+++ b/sw/pc/primer.py
@@ -8,6 +8,7 @@ import sys
 import time
 from binascii import crc32
 from sc64 import SC64
+from sys import exit
 from typing import Callable, Optional