diff --git a/Library/Homebrew/cmd/--prefix.rb b/Library/Homebrew/cmd/--prefix.rb
index 3f4faebaa9..535a7b4227 100644
--- a/Library/Homebrew/cmd/--prefix.rb
+++ b/Library/Homebrew/cmd/--prefix.rb
@@ -3,7 +3,7 @@ module Homebrew
     if ARGV.named.empty?
       puts HOMEBREW_PREFIX
     else
-      puts ARGV.formulae.map{ |f| f.opt_prefix.exist? ? f.opt_prefix : f.installed_prefix }
+      puts ARGV.resolved_formulae.map{ |f| f.opt_prefix.exist? ? f.opt_prefix : f.installed_prefix }
     end
   end
 end