--- base.py
+++ base.py
@@ -1,8 +1,9 @@
+from __future__ import absolute_import
 import os
 
 # Paths are relative to mozilla-central
 config = {
     "package-name": "thunderbird",
     "installer-tag": "comm/mail/installer/windows/app.tag",
     "sfx-stub": "comm/other-licenses/7zstub/thunderbird/7zSD.sfx",
     "stub-installer-tag": "",
