diff --git a/aleksis/apps/chronos/models.py b/aleksis/apps/chronos/models.py
index 945b9d1ed3d53daf6658bb13f0d5668ce0ca656e..a0a36b9680b93c38035d91ae4f578b09bb0d6ed9 100644
--- a/aleksis/apps/chronos/models.py
+++ b/aleksis/apps/chronos/models.py
@@ -450,7 +450,7 @@ class Lesson(ExtensibleModel):
         return CalendarWeek(year=year, week=week)
 
     class Meta:
-        ordering = ["date_start"]
+        ordering = ["date_start", "subject"]
         indexes = [models.Index(fields=["date_start", "date_end"])]
 
 
@@ -559,7 +559,7 @@ class LessonPeriod(ExtensibleModel):
         )
 
     class Meta:
-        ordering = ["lesson__date_start", "period__weekday", "period__period"]
+        ordering = ["lesson__date_start", "period__weekday", "period__period", "lesson__subject"]
         indexes = [models.Index(fields=["lesson", "period"])]