diff --git a/biscuit/apps/chronos/tables.py b/biscuit/apps/chronos/tables.py
index 786479f4b4a4b6346c9b742d95de6a4f5145a7c2..ac2bcb18fd54c045286a638c152788d546d539c7 100644
--- a/biscuit/apps/chronos/tables.py
+++ b/biscuit/apps/chronos/tables.py
@@ -7,7 +7,7 @@ from django_tables2.utils import A
 from .models import LessonPeriod
 
 
-def _css_class_from_lesson_state(record: Optional[LessonPeriod] = None, table: Optional[LessonsTable] = None) -> str:
+def _css_class_from_lesson_state(record: Optional[LessonPeriod] = None, table: Optional[LessonTable] = None) -> str:
     if record.get_substitution(table._week):
         return 'table-warning'
     else: