diff --git a/Library/Homebrew/dependable.rb b/Library/Homebrew/dependable.rb
index 50ff5c90f8..d500cd0331 100644
--- a/Library/Homebrew/dependable.rb
+++ b/Library/Homebrew/dependable.rb
@@ -1,7 +1,7 @@
 require 'options'
 
 module Dependable
-  RESERVED_TAGS = [:build, :optional, :recommended]
+  RESERVED_TAGS = [:build, :optional, :recommended, :run]
 
   def build?
     tags.include? :build
@@ -15,6 +15,10 @@ module Dependable
     tags.include? :recommended
   end
 
+  def run?
+    tags.include? :run
+  end
+
   def required?
     !build? && !optional? && !recommended?
   end