diff --git a/test/unit/app/authnz/test_custos_authnz.py b/test/unit/app/authnz/test_custos_authnz.py
index f0f35ab43b0d..d8cba4ae9e6b 100644
--- a/test/unit/app/authnz/test_custos_authnz.py
+++ b/test/unit/app/authnz/test_custos_authnz.py
@@ -344,7 +344,7 @@ def test_callback_nonce_validation_with_bad_nonce(self):
         self.test_nonce_hash = self.test_nonce_hash + "Z"
 
         # self.custos_authnz._fetch_token = fetch_token
-        with self.assertRaisesRegex(Exception, "^Nonce mismatch!$"):
+        with self.assertRaisesRegex(Exception, "^Nonce mismatch"):
             self.custos_authnz.callback(
                 state_token="xxx",
                 authz_code=self.test_code,