diff --git a/aleksis/apps/alsijil/schema.py b/aleksis/apps/alsijil/schema.py
index 5864f7f02341f7dbb0837b27a5b225f9e579ffd9..7bb0ebfac410f39ab8114bf29dc1428460e6b57b 100644
--- a/aleksis/apps/alsijil/schema.py
+++ b/aleksis/apps/alsijil/schema.py
@@ -233,9 +233,9 @@ class Query(graphene.ObjectType):
                 )  # FIXME: Queries shouldn't alter data
 
         return LessonDocumentation.objects.filter(
-            lesson_period_id__in=LessonPeriod.objects.filter(lesson_id=id).values_list(
-                "id", flat=True
-            )
+            lesson_period_id__in=LessonPeriod.objects.filter(
+                lesson__in=lesson.equal_lessons
+            ).values_list("id", flat=True)
         ).order_by(
             "-year", "-week", "-lesson_period__period__weekday", "-lesson_period__period__period"
         )