diff --git a/tests/aaaaaa/__init__.py b/tests/aaaaaa/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/aaaaaa/models.py b/tests/aaaaaa/models.py
new file mode 100644
index 0000000..e96855d
--- /dev/null
+++ b/tests/aaaaaa/models.py
@@ -0,0 +1,11 @@
+from django.db import models
+
+class ModelManager(models.Manager):
+    def get_queryset(self):
+        return super(ModelManager, self).get_queryset().filter(parent__isnull=False)
+
+class Category(models.Model):
+    parent = models.ForeignKey('Category', to_field='slug', blank=True, null=True, on_delete=models.SET_NULL)
+    slug = models.SlugField()
+
+    vehicle_models = ModelManager()
diff --git a/tests/aaaaaa/tests.py b/tests/aaaaaa/tests.py
new file mode 100644
index 0000000..d51edff
--- /dev/null
+++ b/tests/aaaaaa/tests.py
@@ -0,0 +1,9 @@
+from django.test import TestCase
+
+from .models import Category
+
+
+class ReproTestCase(TestCase):
+    def test_repro(self):
+        qs = Category.vehicle_models.all()
+        self.assertIn('IS NOT NULL', str(qs.query))