diff --git a/Library/Homebrew/dev-cmd/pr-automerge.rb b/Library/Homebrew/dev-cmd/pr-automerge.rb
index f4fe6e1b45..819ca6aa50 100644
--- a/Library/Homebrew/dev-cmd/pr-automerge.rb
+++ b/Library/Homebrew/dev-cmd/pr-automerge.rb
@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 
 require "abstract_command"
+require "tap"
 require "utils/github"
 
 module Homebrew