diff --git a/Library/Homebrew/github_packages.rb b/Library/Homebrew/github_packages.rb
index 7b6014a108..4023989927 100644
--- a/Library/Homebrew/github_packages.rb
+++ b/Library/Homebrew/github_packages.rb
@@ -340,8 +340,6 @@ class GitHubPackages
 
   def write_image_index(manifests, blobs, annotations)
     image_index = {
-      # Currently needed for correct multi-arch display in GitHub Packages UI
-      mediaType:     "application/vnd.docker.distribution.manifest.list.v2+json",
       schemaVersion: 2,
       manifests:     manifests,
       annotations:   annotations,