diff --git a/app/models/upload.rb b/app/models/upload.rb
index 21ab5e9cd..2f32db651 100644
--- a/app/models/upload.rb
+++ b/app/models/upload.rb
@@ -37,7 +37,6 @@ class Upload < ActiveRecord::Base
     def validate_md5_uniqueness
       md5_post = Post.find_by_md5(md5)
       if md5_post
-        merge_tags(md5_post)
         raise "duplicate: #{md5_post.id}"
       end
     end
@@ -119,11 +118,6 @@ class Upload < ActiveRecord::Base
         end
       end
     end
-
-    def merge_tags(post)
-      post.tag_string += " #{tag_string}"
-      post.save
-    end
   end
 
   module FileMethods