diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 7682da5c8..e89ed81e6 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -23,6 +23,7 @@ require "language/python"
 require "tab"
 require "mktemp"
 require "find"
+require "utils/spdx"
 
 # A formula provides instructions and metadata for Homebrew to install a piece
 # of software. Every Homebrew formula is a {Formula}.