diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index b714c22de6..f55ca41444 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1620,6 +1620,7 @@ class Formula
       raise
     end
   end
+  private :extract_macho_slice_from
 
   # an array of all core {Formula} names
   # @private