diff --git a/lib/active_file/sites/disk_site.rb b/lib/active_file/sites/disk_site.rb
index 2466b665c4..9068e14866 100644
--- a/lib/active_file/sites/disk_site.rb
+++ b/lib/active_file/sites/disk_site.rb
@@ -20,22 +20,26 @@ class ActiveFile::Sites::DiskSite < ActiveFile::Site
 
   def download(key)
     if block_given?
-      open(path_for(key)) do |file|
+      File.open(path_for(key)) do |file|
         while data = file.read(65536)
           yield data
         end
       end
     else
-      open(path_for(key), &:read)
+      File.open path_for(key), &:read
     end
   end
 
   def delete(key)
-    File.delete(path_for(key))
+    File.delete path_for(key)
+  end
+
+  def exists?(key)
+    File.exist? path_for(key)
   end
 
   def size(key)
-    File.size(path_for(key))
+    File.size path_for(key)
   end
 
   def checksum(key)
@@ -44,11 +48,11 @@ class ActiveFile::Sites::DiskSite < ActiveFile::Site
 
   private
     def path_for(key)
-      File.join(root, folder_for(key), key)
+      File.join root, folder_for(key), key
     end
 
     def folder_for(key)
-      [key[0..1], key[2..3]].join("/")
+      [ key[0..1], key[2..3] ].join("/")
     end
 
     def make_path_for(key)