diff --git a/app/models/thumbnail.rb b/app/models/thumbnail.rb
index b74df9e..ca36658 100644
--- a/app/models/thumbnail.rb
+++ b/app/models/thumbnail.rb
@@ -1,5 +1,5 @@
 class Thumbnail < ActiveRecord::Base
   has_attachment :storage => :file_system,
-    :content_type => :image
+    :content_type => :image, :max_size => 5.megabytes
   validates_as_attachment
 end
--
libgit2 0.21.2