diff --git a/cachalot/tests/db_router.py b/cachalot/tests/db_router.py
index 841fae0..e7e3267 100644
--- a/cachalot/tests/db_router.py
+++ b/cachalot/tests/db_router.py
@@ -4,8 +4,6 @@ from django.conf import settings
 class PostgresRouter(object):
     @staticmethod
     def in_postgres(model):
-        if model is None:
-            return False
         app_label = model._meta.app_label
         model_name = model._meta.model_name
         return app_label == 'cachalot' and model_name == 'postgresmodel'
@@ -15,5 +13,5 @@ class PostgresRouter(object):
                 else 'default')
 
     def allow_migrate(self, db, app_label, model=None, **hints):
-        if self.in_postgres(model):
+        if model is not None and self.in_postgres(model):
             return db == self.get_postgresql_alias()