diff --git a/app/models/approve_article.rb b/app/models/approve_article.rb
index 2698465..45f9eeb 100644
--- a/app/models/approve_article.rb
+++ b/app/models/approve_article.rb
@@ -48,7 +48,7 @@ class ApproveArticle < Task
   end
 
   def perform
-    article.copy!(:name => name, :abstract => abstract, :body => body, :profile => target, :reference_article => article, :parent => article_parent, :highlighted => highlighted, :source => article.source, :last_changed_by_id => article.author)
+    article.copy!(:name => name, :abstract => abstract, :body => body, :profile => target, :reference_article => article, :parent => article_parent, :highlighted => highlighted, :source => article.source, :last_changed_by_id => article.author.id)
   end
 
   def title
--
libgit2 0.21.2