diff --git a/avatar/providers.py b/avatar/providers.py
index 4c9508b..c72ef75 100644
--- a/avatar/providers.py
+++ b/avatar/providers.py
@@ -34,7 +34,7 @@ class DefaultAvatarProvider(object):
     """
 
     @classmethod
-    def get_avatar_url(self, user, size):
+    def get_avatar_url(cls, user, size):
         return get_default_avatar_url()
 
 
@@ -44,7 +44,7 @@ class PrimaryAvatarProvider(object):
     """
 
     @classmethod
-    def get_avatar_url(self, user, size):
+    def get_avatar_url(cls, user, size):
         avatar = get_primary_avatar(user, size)
         if avatar:
             return avatar.avatar_url(size)
@@ -56,7 +56,7 @@ class GravatarAvatarProvider(object):
     """
 
     @classmethod
-    def get_avatar_url(self, user, size):
+    def get_avatar_url(cls, user, size):
         params = {'s': str(size)}
         if settings.AVATAR_GRAVATAR_DEFAULT:
             params['d'] = settings.AVATAR_GRAVATAR_DEFAULT
@@ -74,7 +74,7 @@ class FacebookAvatarProvider(object):
     """
 
     @classmethod
-    def get_avatar_url(self, user, size):
+    def get_avatar_url(cls, user, size):
         fb_id = get_facebook_id(user)
         if fb_id:
             url = 'https://graph.facebook.com/{fb_id}/picture?type=square&width={size}&height={size}'
@@ -84,24 +84,23 @@ class FacebookAvatarProvider(object):
             )
 
 
-class InitialsAvatarProvider:
+class InitialsAvatarProvider(object):
     """
     Returns a tuple with template_name and context for rendering the given user's avatar as their
     initials in white against a background with random hue based on their primary key.
     """
 
-    def get_avatar_url(user, size):
+    @classmethod
+    def get_avatar_url(cls, user, size):
         initials = user.first_name[:1] + user.last_name[:1]
         if not initials:
             initials = user.username[:1]
         initials = initials.upper()
         context = {
-            'fontsize': (size*1.1)/2,
+            'fontsize': (size * 1.1) / 2,
             'initials': initials,
             'hue': user.pk % 360,
             'saturation': '65%',
             'lightness': '60%',
         }
         return ('avatar/initials.html', context)
-
-