diff --git a/src/agenda_culturel/models.py b/src/agenda_culturel/models.py
index 15d4209..33a9503 100644
--- a/src/agenda_culturel/models.py
+++ b/src/agenda_culturel/models.py
@@ -1655,7 +1655,7 @@ class Event(models.Model):
         for attr in Event.data_fields(all=all, no_m2m=True):
             if attr == "title" and other.has_invalid_title():
                 continue
-            if attr == "start_date" and other.has_invalid_start_date():
+            if attr == "start_day" and other.has_invalid_start_date():
                 continue
             setattr(self, attr, getattr(other, attr))