diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index 60300a0b0f1..da1a6b1b52d 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -447,7 +447,7 @@ class AccountMoveLine(models.Model):
         balance = 0
         for line in self._context['line_ids']:
             if line[2]:
-                balance += line[2]['debit'] - line[2]['credit']
+                balance += line[2].get('debit', 0) - line[2].get('credit', 0)
         if balance < 0:
             rec.update({'debit': -balance})
         if balance > 0: