diff --git a/openwisp_controller/config/tests/test_config.py b/openwisp_controller/config/tests/test_config.py
index 99ca5fc67..3d25f1c6e 100644
--- a/openwisp_controller/config/tests/test_config.py
+++ b/openwisp_controller/config/tests/test_config.py
@@ -652,18 +652,36 @@ def test_remove_duplicate_files(self):
                 ]
             },
         )
-        config = self._create_config(organization=self._get_org())
-        config.templates.add(template1)
-        config.templates.add(template2)
-        config.refresh_from_db()
-        try:
-            result = config.get_backend_instance(
-                template_instances=[template1, template2]
-            ).render()
-        except ValidationError:
-            self.fail('ValidationError raised!')
-        else:
-            self.assertIn('# path: /etc/vpnserver1', result)
+        org = self._get_org()
+        with self.subTest('Test template applied on creating config'):
+            try:
+                config = self._create_config(
+                    organization=org,
+                    templates=[template1, template2],
+                )
+                result = config.get_backend_instance(
+                    template_instances=[template1, template2]
+                ).render()
+            except ValidationError:
+                self.fail('ValidationError raised!')
+            else:
+                self.assertIn('# path: /etc/vpnserver1', result)
+
+        config.device.delete()
+        config.delete()
+        with self.subTest('Test template applied after creating config object'):
+            config = self._create_config(organization=org)
+            config.templates.add(template1)
+            config.templates.add(template2)
+            config.refresh_from_db()
+            try:
+                result = config.get_backend_instance(
+                    template_instances=[template1, template2]
+                ).render()
+            except ValidationError:
+                self.fail('ValidationError raised!')
+            else:
+                self.assertIn('# path: /etc/vpnserver1', result)
 
     def test_duplicated_files_in_config(self):
         try:
diff --git a/openwisp_controller/config/tests/utils.py b/openwisp_controller/config/tests/utils.py
index d5de34cab..90147e3e5 100644
--- a/openwisp_controller/config/tests/utils.py
+++ b/openwisp_controller/config/tests/utils.py
@@ -59,7 +59,10 @@ def _create_config(self, **kwargs):
             options['device'] = self._create_device(
                 organization=self._get_org(), name='test-device'
             )
+        templates = options.pop('templates', [])
         c = Config(**options)
+        if templates:
+            c.templates.set(templates)
         c.full_clean()
         c.save()
         return c