diff --git a/borg/upgrader.py b/borg/upgrader.py
index 461fc7491..119cf7b4e 100644
--- a/borg/upgrader.py
+++ b/borg/upgrader.py
@@ -3,6 +3,7 @@ import logging
 logger = logging.getLogger(__name__)
 import os
 import shutil
+import sys
 import time
 
 from .helpers import get_keys_dir, get_cache_dir