diff --git a/wagtail/tests/testapp/migrations/0005_image_file_size.py b/wagtail/tests/testapp/migrations/0005_image_file_size.py
new file mode 100644
index 000000000..0e8c2a192
--- /dev/null
+++ b/wagtail/tests/testapp/migrations/0005_image_file_size.py
@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('tests', '0004_streammodel_richtext'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='customimagewithadminformfields',
+            name='file_size',
+            field=models.PositiveIntegerField(null=True, editable=False),
+        ),
+        migrations.AddField(
+            model_name='customimagewithoutadminformfields',
+            name='file_size',
+            field=models.PositiveIntegerField(null=True, editable=False),
+        ),
+    ]