diff --git a/Library/Homebrew/dev-cmd/generate-cask-api.rb b/Library/Homebrew/dev-cmd/generate-cask-api.rb
index 864e7e6bff..d72b20118e 100644
--- a/Library/Homebrew/dev-cmd/generate-cask-api.rb
+++ b/Library/Homebrew/dev-cmd/generate-cask-api.rb
@@ -64,6 +64,8 @@ module Homebrew
 
           homebrew_cask_tap_json = JSON.generate(tap.to_internal_api_hash)
           File.write("api/internal/v3/homebrew-cask.json", homebrew_cask_tap_json) unless args.dry_run?
+          canonical_json = JSON.pretty_generate(tap.cask_renames)
+          File.write("_data/cask_canonical.json", "#{canonical_json}\n") unless args.dry_run?
         end
       end