diff --git a/app/models/wiki_content.rb b/app/models/wiki_content.rb
index a72686b78589fb7b0526d6513e22889f61e477ee..d206be97d8ec9f6c0cf170d8ebc23fb8329fcd0f 100644
--- a/app/models/wiki_content.rb
+++ b/app/models/wiki_content.rb
@@ -22,7 +22,7 @@ class WikiContent < ActiveRecord::Base
   belongs_to :page, :class_name => 'WikiPage', :foreign_key => 'page_id'
   belongs_to :author, :class_name => 'User', :foreign_key => 'author_id'
   validates_presence_of :text
-  validates_length_of :comments, :maximum => 255
+  validates_length_of :comments, :maximum => 255, :allow_nil => true
   
   acts_as_versioned
   class Version