diff --git a/biscuit/apps/chronos/models.py b/biscuit/apps/chronos/models.py
index 1bf172e468f2872da2042a2feacab5f647a2041a..003ef501b6862877e7b38996d4d4aa4bf4ff67a3 100644
--- a/biscuit/apps/chronos/models.py
+++ b/biscuit/apps/chronos/models.py
@@ -138,7 +138,7 @@ class LessonPeriod(SchoolRelated):
         # prefetching when this model is loaded from outside, in contrast
         # to .filter()
         for substitution in self.substitutions.all():
-            if substitution.weeb == wanted_week:
+            if substitution.week == wanted_week:
                 return substitution
         return None