diff --git a/src/openforms/registrations/contrib/microsoft_graph/migrations/0003_alter_msgraphregistrationconfig_service.py b/src/openforms/registrations/contrib/microsoft_graph/migrations/0003_alter_msgraphregistrationconfig_service.py
new file mode 100644
index 0000000000..b4c6e2f308
--- /dev/null
+++ b/src/openforms/registrations/contrib/microsoft_graph/migrations/0003_alter_msgraphregistrationconfig_service.py
@@ -0,0 +1,27 @@
+# Generated by Django 3.2.21 on 2023-11-13 11:43
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("microsoft", "0003_auto_20211210_1804"),
+        ("registrations_microsoft_graph", "0002_auto_20211210_1804"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="msgraphregistrationconfig",
+            name="service",
+            field=models.OneToOneField(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.PROTECT,
+                related_name="registration_config",
+                to="microsoft.msgraphservice",
+                verbose_name="Microsoft Graph service",
+            ),
+        ),
+    ]
diff --git a/src/openforms/registrations/contrib/microsoft_graph/models.py b/src/openforms/registrations/contrib/microsoft_graph/models.py
index 984bdc1ee8..86e38e4eab 100644
--- a/src/openforms/registrations/contrib/microsoft_graph/models.py
+++ b/src/openforms/registrations/contrib/microsoft_graph/models.py
@@ -19,6 +19,7 @@ class MSGraphRegistrationConfig(SingletonModel):
         verbose_name=_("Microsoft Graph service"),
         on_delete=models.PROTECT,
         related_name="registration_config",
+        blank=True,
         null=True,
     )