diff --git a/aleksis/apps/alsijil/data_checks.py b/aleksis/apps/alsijil/data_checks.py
index cfb727fba4d95887a486df1d2d3e8e3f2ec06f00..be36446beaf9d1bfc2474df29242f47a23d9a1c8 100644
--- a/aleksis/apps/alsijil/data_checks.py
+++ b/aleksis/apps/alsijil/data_checks.py
@@ -56,11 +56,15 @@ class NoPersonalNotesInCancelledLessonsDataCheck(DataCheck):
     def check_data(cls):
         from .models import PersonalNote
 
-        personal_notes = PersonalNote.objects.filter(
-            lesson_period__substitutions__cancelled=True,
-            lesson_period__substitutions__week=F("week"),
-            lesson_period__substitutions__year=F("year"),
-        ).prefetch_related("lesson_period", "lesson_period__substitutions")
+        personal_notes = (
+            PersonalNote.objects.not_empty()
+            .filter(
+                lesson_period__substitutions__cancelled=True,
+                lesson_period__substitutions__week=F("week"),
+                lesson_period__substitutions__year=F("year"),
+            )
+            .prefetch_related("lesson_period", "lesson_period__substitutions")
+        )
 
         for note in personal_notes:
             logging.info(f"Check personal note {note}")
@@ -119,7 +123,9 @@ class LessonDocumentationOnHolidaysDataCheck(DataCheck):
 
         holidays = Holiday.objects.all()
 
-        documentations = LessonDocumentation.objects.not_empty().annotate(actual_date=weekday_to_date)
+        documentations = LessonDocumentation.objects.not_empty().annotate(
+            actual_date=weekday_to_date
+        )
 
         q = Q()
         for holiday in holidays: