diff --git a/tests/test_expressions.py b/tests/test_expressions.py
index 8abc57a..79ce45f 100644
--- a/tests/test_expressions.py
+++ b/tests/test_expressions.py
@@ -32,7 +32,7 @@ class LocalizedExpressionsTestCase(TestCase):
         cls.TestModel2 = get_fake_model(
             {
                 'text': LocalizedField(),
-                'other': models.ForeignKey(cls.TestModel1, related_name='features')
+                'other': models.ForeignKey(cls.TestModel1, related_name='features', on_delete=models.CASCADE)
             }
         )
 
diff --git a/tests/test_slug_fields.py b/tests/test_slug_fields.py
index 4d2d172..96b0772 100644
--- a/tests/test_slug_fields.py
+++ b/tests/test_slug_fields.py
@@ -175,7 +175,7 @@ class LocalizedSlugFieldTestCase(TestCase):
         model = get_fake_model(
             {
                 'title': LocalizedField(),
-                'other': models.ForeignKey(model_fk),
+                'other': models.ForeignKey(model_fk, on_delete=models.CASCADE),
                 'slug': LocalizedUniqueSlugField(populate_from=('title', 'other.name'))
             }
         )