diff --git a/modoboa/lib/throttle.py b/modoboa/lib/throttle.py
index c52de265d..d972742be 100644
--- a/modoboa/lib/throttle.py
+++ b/modoboa/lib/throttle.py
@@ -1,8 +1,12 @@
 from rest_framework.throttling import SimpleRateThrottle, UserRateThrottle
 from django.urls import resolve
 
+
 class UserDdosPerView(SimpleRateThrottle):
-    """Custom Throttle class for rest_framework. The throttling is applied on a per view basis for authentificated users."""
+    """
+    Custom Throttle class for rest_framework. The throttling is
+    applied on a per view basis for authentificated users.
+    """
 
     scope = 'ddos'
 
@@ -17,29 +21,22 @@ class UserDdosPerView(SimpleRateThrottle):
         }
 
 
-class UserLesserDdosUser(SimpleRateThrottle):
-    """Custom Throttle class for rest_framework. The throttling is applied on a per view basis for authentificated users."""
+class UserLesserDdosUser(UserDdosPerView):
+    """
+    Custom Throttle class for rest_framework. The throttling is
+    applied on a per view basis for authentificated users.
+    """
 
     scope = 'ddos_lesser'
 
-    def get_cache_key(self, request, view):
-        if request.user and request.user.is_authenticated:
-            ident = request.user.pk
-        else:
-            ident = self.get_ident(request)
-        return self.cache_format % {
-            'scope': hash(resolve(request.path).url_name),
-            'ident': ident
-        }
-
 
 class LoginThrottle(SimpleRateThrottle):
-    """ Custom throttle to reset the cache counter on success. """
+    """Custom throttle to reset the cache counter on success."""
 
     scope = 'login'
 
     def get_cache_key(self, request, view):
-            return self.cache_format % {
+        return self.cache_format % {
             'scope': self.scope,
             'ident': self.get_ident(request)
         }
@@ -64,16 +61,22 @@ class PasswordResetApplyThrottle(LoginThrottle):
     scope = 'password_recovery_apply'
 
 
-class GetThrottleViewsetMixin():
-    """Override default get_throttle behaviour to assign throttle classes to different actions."""
+class GetThrottleViewsetMixin:
+    """
+    Override default get_throttle behaviour to assign throttle
+    classes to different actions.
+    """
 
     def get_throttles(self):
         """Give lesser_ddos to GET type actions and ddos to others."""
 
         throttles = [UserRateThrottle()]
-    
-        if self.action in ["list", "retrieve", "validate", "dns_detail", "me", "dns_detail", "applications", "structure"]:
+        actions = [
+            "list", "retrieve", "validate", "dns_detail", "me",
+            "dns_detail", "applications", "structure"
+        ]
+        if self.action in actions:
             throttles.append(UserLesserDdosUser())
         else:
             throttles.append(UserDdosPerView())
-        return throttles
\ No newline at end of file
+        return throttles
diff --git a/modoboa/limits/api/v1/viewsets.py b/modoboa/limits/api/v1/viewsets.py
index 2e3da9e5d..006cb7454 100644
--- a/modoboa/limits/api/v1/viewsets.py
+++ b/modoboa/limits/api/v1/viewsets.py
@@ -10,7 +10,8 @@ from modoboa.lib.throttle import GetThrottleViewsetMixin
 from . import serializers
 
 
-class ResourcesViewSet(GetThrottleViewsetMixin,
+class ResourcesViewSet(
+        GetThrottleViewsetMixin,
         mixins.RetrieveModelMixin,
         mixins.UpdateModelMixin,
         viewsets.GenericViewSet):