diff --git a/src/design/plone/policy/tests/test_limit_submit_form.py b/src/design/plone/policy/tests/test_limit_submit_form.py
index fe2bb0b..75c2c44 100644
--- a/src/design/plone/policy/tests/test_limit_submit_form.py
+++ b/src/design/plone/policy/tests/test_limit_submit_form.py
@@ -169,7 +169,5 @@ def test_unique_field(self):
         transaction.commit()
         self.assertEqual(response.status_code, 500)
         # test message is not fair because it's a translation, in another package
-        self.assertTrue(
-            "Value not unique" in response.json()["message"]
-            or "non sono univoci" in response.json()["message"]
-        )
+        message = response.json()["message"]
+        self.assertTrue("Value not unique" in message or "non sono univoci" in message)