diff --git a/app/logical/s3_backup_service.rb b/app/logical/s3_backup_service.rb
index fe55cb966..156f7926f 100644
--- a/app/logical/s3_backup_service.rb
+++ b/app/logical/s3_backup_service.rb
@@ -12,6 +12,11 @@ class S3BackupService < BackupService
     upload_to_s3(key, file_path)
   end
 
+  def delete(file_path, type: nil)
+    key = s3_key(file_path, type)
+    delete_from_s3(key)
+  end
+
 protected
   def s3_key(file_path, type)
     case type
@@ -26,6 +31,12 @@ protected
     end
   end
 
+  def delete_from_s3(key)
+    client.delete_object(bucket: bucket, key: key)
+  rescue Aws::S3::Errors::NoSuchKey
+    # ignore
+  end
+
   def upload_to_s3(key, file_path)
     File.open(file_path, "rb") do |body|
       base64_md5 = Digest::MD5.base64digest(File.read(file_path))
diff --git a/app/models/post.rb b/app/models/post.rb
index 98f6a638c..2c19821c7 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -74,6 +74,10 @@ class Post < ApplicationRecord
           end
         end
 
+        backup_service.delete(file_path, type: :original)
+        backup_service.delete(large_file_path, type: :large)
+        backup_service.delete(preview_file_path, type: :preview)
+
         # the large file and the preview don't necessarily exist. if so errors will be ignored.
         FileUtils.rm_f(file_path)
         FileUtils.rm_f(large_file_path)
diff --git a/app/models/post_replacement.rb b/app/models/post_replacement.rb
index b2c85c4e3..ef5d03373 100644
--- a/app/models/post_replacement.rb
+++ b/app/models/post_replacement.rb
@@ -18,11 +18,6 @@ class PostReplacement < ApplicationRecord
   end
 
   def process!
-    # 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.")
-    end
-
     transaction do
       upload = Upload.create!(file: replacement_file, source: replacement_url, rating: post.rating, tag_string: self.tags)
       upload.process_upload