diff --git a/ihatemoney/models.py b/ihatemoney/models.py
index 2313b179..da7c5cf8 100644
--- a/ihatemoney/models.py
+++ b/ihatemoney/models.py
@@ -6,6 +6,7 @@ from flask import g, current_app
 
 from debts import settle
 from sqlalchemy import orm
+from sqlalchemy.sql import func
 from itsdangerous import (
     TimedJSONWebSignatureSerializer,
     URLSafeSerializer,