diff --git a/Library/Homebrew/cmd/postinstall.rb b/Library/Homebrew/cmd/postinstall.rb
index 9009803559..1936f25ea3 100644
--- a/Library/Homebrew/cmd/postinstall.rb
+++ b/Library/Homebrew/cmd/postinstall.rb
@@ -2,7 +2,7 @@ require "sandbox"
 
 module Homebrew
   def postinstall
-    ARGV.formulae.each { |f| run_post_install(f) }
+    ARGV.resolved_formulae.each { |f| run_post_install(f) }
   end
 
   def run_post_install(formula)