diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 7a7c72b99efa204b0fac0d67031a938f904a554d..d941adfc7556c5852b631f792ec0ad2a3ca1aac2 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -13,6 +13,7 @@ Fixed
 ~~~~~
 
 * Fix problems with displaying dates for events in the week and lesson view.
+* Unique constraint on lesson documentations and personal notes did not work and caused racey duplicates.
 
 `2.0rc5`_ - 2021-08-12
 ----------------------
diff --git a/aleksis/apps/alsijil/migrations/0014_fix_unique_lesson_documentation.py b/aleksis/apps/alsijil/migrations/0014_fix_unique_lesson_documentation.py
new file mode 100644
index 0000000000000000000000000000000000000000..6ed00ec72a1a23e8bfbde5d765324cd6f59275a3
--- /dev/null
+++ b/aleksis/apps/alsijil/migrations/0014_fix_unique_lesson_documentation.py
@@ -0,0 +1,29 @@
+# Generated by Django 3.2.3 on 2021-08-20 12:38
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('alsijil', '0013_fix_uniqueness_per_site'),
+    ]
+
+    operations = [
+        migrations.RemoveConstraint(
+            model_name='lessondocumentation',
+            name='unique_documentation_per_object',
+        ),
+        migrations.AddConstraint(
+            model_name='lessondocumentation',
+            constraint=models.UniqueConstraint(fields=('week', 'year', 'lesson_period'), name='unique_documentation_per_lp'),
+        ),
+        migrations.AddConstraint(
+            model_name='lessondocumentation',
+            constraint=models.UniqueConstraint(fields=('week', 'year', 'event'), name='unique_documentation_per_ev'),
+        ),
+        migrations.AddConstraint(
+            model_name='lessondocumentation',
+            constraint=models.UniqueConstraint(fields=('week', 'year', 'extra_lesson'), name='unique_documentation_per_el'),
+        ),
+    ]
diff --git a/aleksis/apps/alsijil/migrations/0015_fix_unique_personal_note.py b/aleksis/apps/alsijil/migrations/0015_fix_unique_personal_note.py
new file mode 100644
index 0000000000000000000000000000000000000000..195e0ec80ef43a4d8afe8bb38193d954f833aef1
--- /dev/null
+++ b/aleksis/apps/alsijil/migrations/0015_fix_unique_personal_note.py
@@ -0,0 +1,29 @@
+# Generated by Django 3.2.4 on 2021-08-29 13:31
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('alsijil', '0014_fix_unique_lesson_documentation'),
+    ]
+
+    operations = [
+        migrations.RemoveConstraint(
+            model_name='personalnote',
+            name='unique_personal_note_per_object',
+        ),
+        migrations.AddConstraint(
+            model_name='personalnote',
+            constraint=models.UniqueConstraint(fields=('week', 'year', 'lesson_period', 'person'), name='unique_note_per_lp'),
+        ),
+        migrations.AddConstraint(
+            model_name='personalnote',
+            constraint=models.UniqueConstraint(fields=('week', 'year', 'event', 'person'), name='unique_note_per_ev'),
+        ),
+        migrations.AddConstraint(
+            model_name='personalnote',
+            constraint=models.UniqueConstraint(fields=('week', 'year', 'extra_lesson', 'person'), name='unique_note_per_el'),
+        ),
+    ]
diff --git a/aleksis/apps/alsijil/models.py b/aleksis/apps/alsijil/models.py
index 51857750b434dc03b36c23b7c10f6fcca69ed013..1c9cc995142510570db89f18a85ec9b2eaba9ba5 100644
--- a/aleksis/apps/alsijil/models.py
+++ b/aleksis/apps/alsijil/models.py
@@ -283,8 +283,13 @@ class PersonalNote(RegisterObjectRelatedMixin, ExtensibleModel):
                 check=lesson_related_constraint_q, name="one_relation_only_personal_note"
             ),
             models.UniqueConstraint(
-                fields=("lesson_period", "week", "year", "event", "extra_lesson"),
-                name="unique_personal_note_per_object",
+                fields=("week", "year", "lesson_period", "person"), name="unique_note_per_lp",
+            ),
+            models.UniqueConstraint(
+                fields=("week", "year", "event", "person"), name="unique_note_per_ev",
+            ),
+            models.UniqueConstraint(
+                fields=("week", "year", "extra_lesson", "person"), name="unique_note_per_el",
             ),
         ]
 
@@ -373,8 +378,13 @@ class LessonDocumentation(RegisterObjectRelatedMixin, ExtensibleModel):
                 check=lesson_related_constraint_q, name="one_relation_only_lesson_documentation",
             ),
             models.UniqueConstraint(
-                fields=("lesson_period", "week", "year", "event", "extra_lesson"),
-                name="unique_documentation_per_object",
+                fields=("week", "year", "lesson_period"), name="unique_documentation_per_lp",
+            ),
+            models.UniqueConstraint(
+                fields=("week", "year", "event"), name="unique_documentation_per_ev",
+            ),
+            models.UniqueConstraint(
+                fields=("week", "year", "extra_lesson"), name="unique_documentation_per_el",
             ),
         ]