diff --git a/Library/Homebrew/extend/ENV.rb b/Library/Homebrew/extend/ENV.rb
index 8d971eb938..b2650e8511 100644
--- a/Library/Homebrew/extend/ENV.rb
+++ b/Library/Homebrew/extend/ENV.rb
@@ -436,6 +436,7 @@ class << ENV
 
   # Snow Leopard defines an NCURSES value the opposite of most distros
   # See: http://bugs.python.org/issue6848
+  # Currently only used by aalib in core
   def ncurses_define
     append 'CPPFLAGS', "-DNCURSES_OPAQUE=0"
   end