diff --git a/tests/test_odm2/test_readservice.py b/tests/test_odm2/test_readservice.py
index 1297e6b..ec9d158 100644
--- a/tests/test_odm2/test_readservice.py
+++ b/tests/test_odm2/test_readservice.py
@@ -186,10 +186,7 @@ def test_getRelatedModelsByCode(self):
 
         # test invalid argument
         resapi = self.reader.getRelatedModels(code = 234123)
-        assert resapi == []
-        # MySQL is very relaxed about this,
-        # should be `resapi is None` if PostgreSQL,
-        # because code type is not string
+        assert not resapi