diff --git a/wagtail/migrations/0082_alter_workflowstate_content_type_notnull.py b/wagtail/migrations/0082_alter_workflowstate_content_type_notnull.py
new file mode 100644
index 0000000000..86bba23c97
--- /dev/null
+++ b/wagtail/migrations/0082_alter_workflowstate_content_type_notnull.py
@@ -0,0 +1,33 @@
+# Generated by Django 4.2.dev20221212151407 on 2022-12-12 15:38
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("contenttypes", "0002_remove_content_type_name"),
+        ("wagtailcore", "0081_populate_workflowstate_content_type"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="workflowstate",
+            name="base_content_type",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="+",
+                to="contenttypes.contenttype",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="workflowstate",
+            name="content_type",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="+",
+                to="contenttypes.contenttype",
+            ),
+        ),
+    ]
diff --git a/wagtail/models/__init__.py b/wagtail/models/__init__.py
index 01491b2e47..599e78dca0 100644
--- a/wagtail/models/__init__.py
+++ b/wagtail/models/__init__.py
@@ -3855,10 +3855,10 @@ class WorkflowState(models.Model):
     )
 
     content_type = models.ForeignKey(
-        ContentType, on_delete=models.CASCADE, related_name="+", null=True
+        ContentType, on_delete=models.CASCADE, related_name="+"
     )
     base_content_type = models.ForeignKey(
-        ContentType, on_delete=models.CASCADE, related_name="+", null=True
+        ContentType, on_delete=models.CASCADE, related_name="+"
     )
     object_id = models.CharField(max_length=255, verbose_name=_("object id"))