diff --git a/boards/utils.py b/boards/utils.py
--- a/boards/utils.py
+++ b/boards/utils.py
@@ -72,15 +72,20 @@ def get_websocket_token(user_id='', time
     return token
 
 
+# TODO Test this carefully
 def cached_result(key_method=None):
     """
     Caches method result in the Django's cache system, persisted by object name,
-    object name and model id if object is a Django model.
+    object name, model id if object is a Django model, args and kwargs if any.
     """
     def _cached_result(function):
         def inner_func(obj, *args, **kwargs):
-            # TODO Include method arguments to the cache key
             cache_key_params = [obj.__class__.__name__, function.__name__]
+
+            cache_key_params += args
+            for key, value in kwargs:
+                cache_key_params.append(key + ':' + value)
+
             if isinstance(obj, Model):
                 cache_key_params.append(str(obj.id))
 
diff --git a/boards/views/authors.py b/boards/views/authors.py
--- a/boards/views/authors.py
+++ b/boards/views/authors.py
@@ -4,6 +4,7 @@ from django.shortcuts import render
 
 import neboard
 from boards.authors import authors
+from boards.utils import cached_result
 from boards.views.base import BaseBoardView
 from boards.models import Post
 
@@ -23,6 +24,7 @@ class AuthorsView(BaseBoardView):
 
         return render(request, 'boards/authors.html', params)
 
+    @cached_result()
     def _get_directory_size(self, directory):
         total_size = 0
         for dirpath, dirnames, filenames in os.walk(directory):