diff --git a/scripts/lib/check-database-compatibility.py b/scripts/lib/check-database-compatibility.py
index 81efe91dd1..02120ee5ad 100755
--- a/scripts/lib/check-database-compatibility.py
+++ b/scripts/lib/check-database-compatibility.py
@@ -20,6 +20,14 @@ from django.db.migrations.loader import MigrationLoader
 django.setup()
 loader = MigrationLoader(connection)
 missing = set(loader.applied_migrations)
+
+# Ignore django-guardian, which we installed until 1.7.0~3134
+missing.discard(("guardian", "0001_initial"))
+
+# Ignore django.contrib.sites, which we installed until 2.0.0-rc1~984.
+missing.discard(("sites", "0001_initial"))
+missing.discard(("sites", "0002_alter_domain_unique"))
+
 for key, migration in loader.disk_migrations.items():
     missing.discard(key)
     missing.difference_update(migration.replaces)