diff --git a/Library/Homebrew/dependencies.rb b/Library/Homebrew/dependencies.rb
index 455b42e24c..385d54845e 100644
--- a/Library/Homebrew/dependencies.rb
+++ b/Library/Homebrew/dependencies.rb
@@ -74,6 +74,10 @@ class Dependency
     @name == other_dep.to_s
   end
 
+  def <=>(other_dep)
+    @name <=> other_dep.to_s
+  end
+
   def options
     @tags.select{|p|p.start_with? '--'}
   end