diff --git a/taiga/base/permissions.py b/taiga/base/permissions.py
index 3fcc4c18..f34c0596 100644
--- a/taiga/base/permissions.py
+++ b/taiga/base/permissions.py
@@ -23,16 +23,21 @@ def has_project_perm(user, project, perm):
     if user.is_authenticated():
         try:
             membership = Membership.objects.get(project=project, user=user)
-            if membership.role.permissions.filter(codename=perm).count() > 0:
-                return True
-
+            return membership.role.permissions.filter(codename=perm).exists()
         except Membership.DoesNotExist:
             pass
 
     return False
 
 
-class BasePermission(permissions.BasePermission):
+class Permission(permissions.BasePermission):
+    """
+    Base permission class.
+    """
+    pass
+
+
+class BasePermission(Permission):
     get_permission = None
     post_permission = None
     put_permission = None
diff --git a/taiga/base/serializers.py b/taiga/base/serializers.py
index 8e6d72b7..634f0ae0 100644
--- a/taiga/base/serializers.py
+++ b/taiga/base/serializers.py
@@ -41,6 +41,7 @@ class JsonField(serializers.WritableField):
     def from_native(self, data):
         return data
 
+
 class AutoDomainField(serializers.WritableField):
     """
     Automatically set domain field serializer.
diff --git a/taiga/base/utils/dicts.py b/taiga/base/utils/dicts.py
index 512a044d..2d7e7077 100644
--- a/taiga/base/utils/dicts.py
+++ b/taiga/base/utils/dicts.py
@@ -16,7 +16,6 @@
 
 import collections
 
-
 def dict_sum(*args):
     result = collections.Counter()
     for arg in args: