diff --git a/app/models/post_replacement.rb b/app/models/post_replacement.rb
index 9cd52a02b..0917e4d19 100644
--- a/app/models/post_replacement.rb
+++ b/app/models/post_replacement.rb
@@ -17,11 +17,6 @@ class PostReplacement < ActiveRecord::Base
   end
 
   def process!
-    # TODO for ugoiras we need to replace the frame data.
-    if post.is_ugoira?
-      raise NotImplementedError.new("Replacing ugoira images not yet supported.")
-    end
-
     # TODO images hosted on s3 need to be deleted from s3 instead of the local filesystem.
     if Danbooru.config.use_s3_proxy?(post)
       raise NotImplementedError.new("Replacing S3 hosted images not yet supported.")
@@ -45,6 +40,7 @@ class PostReplacement < ActiveRecord::Base
       post.source = upload.source
       post.tag_string = upload.tag_string
       rescale_notes
+      update_ugoira_frame_data(upload)
 
       post.comments.create!({creator: User.system, body: comment_replacement_message, do_not_bump_post: true}, without_protection: true)
       ModAction.log(modaction_replacement_message)
@@ -67,6 +63,11 @@ class PostReplacement < ActiveRecord::Base
     end
   end
 
+  def update_ugoira_frame_data(upload)
+    post.pixiv_ugoira_frame_data.destroy if post.pixiv_ugoira_frame_data.present?
+    upload.ugoira_service.save_frame_data(post) if post.is_ugoira?
+  end
+
   module SearchMethods
     def search(params = {})
       q = all
diff --git a/test/unit/post_replacement_test.rb b/test/unit/post_replacement_test.rb
index 3bba669f6..293de1943 100644
--- a/test/unit/post_replacement_test.rb
+++ b/test/unit/post_replacement_test.rb
@@ -153,5 +153,22 @@ class PostReplacementTest < ActiveSupport::TestCase
         assert_not(File.exists?(old_large_file_path))
       end
     end
+
+    context "a post that is replaced by a ugoira" do
+      should "save the frame data" do
+        @post.replace!(replacement_url: "http://www.pixiv.net/member_illust.php?mode=medium&illust_id=62247364")
+        @post.reload
+
+        assert_equal(80, @post.image_width)
+        assert_equal(82, @post.image_height)
+        assert_equal(2804, @post.file_size)
+        assert_equal("zip", @post.file_ext)
+        assert_equal("cad1da177ef309bf40a117c17b8eecf5", @post.md5)
+        assert_equal("cad1da177ef309bf40a117c17b8eecf5", Digest::MD5.file(@post.file_path).hexdigest)
+
+        assert_equal("https://i1.pixiv.net/img-zip-ugoira/img/2017/04/04/08/57/38/62247364_ugoira1920x1080.zip", @post.source)
+        assert_equal([{"file"=>"000000.jpg", "delay"=>125}, {"file"=>"000001.jpg", "delay"=>125}], @post.pixiv_ugoira_frame_data.data)
+      end
+    end
   end
 end