diff --git a/src/polymorphic/tests/migrations/0001_initial.py b/src/polymorphic/tests/migrations/0001_initial.py
index 34ad0bb..3bd2f78 100644
--- a/src/polymorphic/tests/migrations/0001_initial.py
+++ b/src/polymorphic/tests/migrations/0001_initial.py
@@ -1,4 +1,4 @@
-# Generated by Django 4.2.26 on 2025-12-04 12:57
+# Generated by Django 4.2.26 on 2025-12-05 02:34
 
 from django.db import migrations, models
 import django.db.models.deletion
@@ -256,7 +256,6 @@ class Migration(migrations.Migration):
             ],
             options={
                 'abstract': False,
-                'base_manager_name': 'objects',
             },
             bases=(polymorphic.showfields.ShowFieldTypeAndContent, models.Model),
         ),
@@ -586,7 +585,6 @@ class Migration(migrations.Migration):
             ],
             options={
                 'abstract': False,
-                'base_manager_name': 'objects',
             },
             bases=('tests.relationbase',),
         ),
@@ -598,7 +596,6 @@ class Migration(migrations.Migration):
             ],
             options={
                 'abstract': False,
-                'base_manager_name': 'objects',
             },
             bases=('tests.relationbase',),
         ),
@@ -1060,7 +1057,6 @@ class Migration(migrations.Migration):
             ],
             options={
                 'abstract': False,
-                'base_manager_name': 'objects',
             },
             bases=('tests.relationb',),
         ),
diff --git a/src/polymorphic/tests/models.py b/src/polymorphic/tests/models.py
index 6dfe6e2..5a4c44e 100644
--- a/src/polymorphic/tests/models.py
+++ b/src/polymorphic/tests/models.py
@@ -109,7 +109,13 @@ class Enhance_Inherit(Enhance_Base, Enhance_Plain):
     field_i = models.CharField(max_length=30)
 
 
-class RelationBase(ShowFieldTypeAndContent, PolymorphicModel):
+class RelationAbstractModel(models.Model):
+    class Meta:
+        abstract = True
+
+
+# class RelationBase(ShowFieldTypeAndContent, PolymorphicModel, RelationAbstractModel):  # this works!
+class RelationBase(RelationAbstractModel, ShowFieldTypeAndContent, PolymorphicModel):
     field_base = models.CharField(max_length=30)
     fk = models.ForeignKey(
         "self", on_delete=models.CASCADE, null=True, related_name="relationbase_set"