diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 9554c424c8..78e2dcf931 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -98,6 +98,8 @@ class Formula
     @pin = FormulaPin.new(self)
   end
 
+  private
+
   def set_spec(name)
     spec = self.class.send(name)
     if spec.url
@@ -119,6 +121,8 @@ class Formula
     end
   end
 
+  public
+
   def stable?
     active_spec == stable
   end