diff --git a/modoboa/admin/api/v2/tests.py b/modoboa/admin/api/v2/tests.py
index d1cec2bd2..36a8afc97 100644
--- a/modoboa/admin/api/v2/tests.py
+++ b/modoboa/admin/api/v2/tests.py
@@ -224,10 +224,14 @@ class AccountViewSetTestCase(ModoAPITestCase):
         self.assertIn("password", resp.json())
 
     def test_validate(self):
+        """Test validate and throttling."""
         data = {"username": "toto@test.com"}
         url = reverse("v2:account-validate")
         resp = self.client.post(url, data, format="json")
         self.assertEqual(resp.status_code, 204)
+        for _ in range(500):
+            resp = self.client.post(url, data, format="json")
+        self.assertEqual(resp.status_code, 429)
 
     def test_random_password(self):
         url = reverse("v2:account-random-password")
diff --git a/modoboa/lib/throttle.py b/modoboa/lib/throttle.py
index 03c8cf7c2..32af019ec 100644
--- a/modoboa/lib/throttle.py
+++ b/modoboa/lib/throttle.py
@@ -12,6 +12,6 @@ class UserDosThrottle(SimpleRateThrottle):
             ident = self.get_ident(request)
 
         return self.cache_format % {
-            'scope': id(view),
+            'scope': id(view.action),
             'ident': ident
         }
\ No newline at end of file
diff --git a/test_project/test_project/settings.py b/test_project/test_project/settings.py
index e120e2e95..2d26a543f 100644
--- a/test_project/test_project/settings.py
+++ b/test_project/test_project/settings.py
@@ -194,7 +194,7 @@ REST_FRAMEWORK = {
     'DEFAULT_THROTTLE_RATES': {
         'anon': '100/hour',
         'login': '3/minute',
-        'ddos': '100/minute',
+        'ddos': '300/minute',
         'password_recovery_request': '6/hour',
         'password_recovery_totp_check': '20/hour',
         'password_recovery_apply': '20/hour'