diff --git a/Library/Homebrew/dev-cmd/generate-cask-api.rb b/Library/Homebrew/dev-cmd/generate-cask-api.rb
index adaa75fb69..1bbd987fcf 100644
--- a/Library/Homebrew/dev-cmd/generate-cask-api.rb
+++ b/Library/Homebrew/dev-cmd/generate-cask-api.rb
@@ -49,6 +49,8 @@ module Homebrew
       directories = ["_data/cask", "api/cask", "api/cask-source", "cask"].freeze
       FileUtils.rm_rf directories
       FileUtils.mkdir_p directories
+
+      File.write("api/cask_tap_migrations.json", JSON.dump(tap.tap_migrations))
     end
 
     Homebrew.with_no_api_env do
diff --git a/Library/Homebrew/dev-cmd/generate-formula-api.rb b/Library/Homebrew/dev-cmd/generate-formula-api.rb
index b0ad6ee3e7..462c97bf8f 100644
--- a/Library/Homebrew/dev-cmd/generate-formula-api.rb
+++ b/Library/Homebrew/dev-cmd/generate-formula-api.rb
@@ -50,6 +50,8 @@ module Homebrew
       directories = ["_data/formula", "api/formula", "formula"]
       FileUtils.rm_rf directories + ["_data/formula_canonical.json"]
       FileUtils.mkdir_p directories
+
+      File.write("api/formula_tap_migrations.json", JSON.dump(tap.tap_migrations))
     end
 
     Homebrew.with_no_api_env do