diff --git a/Library/Homebrew/extend/ARGV.rb b/Library/Homebrew/extend/ARGV.rb
index afb0386974..fc3039cc80 100644
--- a/Library/Homebrew/extend/ARGV.rb
+++ b/Library/Homebrew/extend/ARGV.rb
@@ -89,7 +89,7 @@ module HomebrewArgvExtension
   end
 
   def build_head?
-    flag? '--HEAD'
+    include? '--HEAD'
   end
 
   def build_devel?