diff --git a/app/models/post.rb b/app/models/post.rb
index 965f7b150..651776144 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -591,7 +591,7 @@ class Post < ActiveRecord::Base
     def add_automatic_tags(tags)
       return tags if !Danbooru.config.enable_dimension_autotagging
 
-      tags -= %w(incredibly_absurdres absurdres highres lowres huge_filesize animated_gif flash webm)
+      tags -= %w(incredibly_absurdres absurdres highres lowres huge_filesize animated_gif flash webm mp4)
 
       if has_dimensions?
         if image_width >= 10_000 || image_height >= 10_000