diff --git a/Library/Homebrew/cmd/update.rb b/Library/Homebrew/cmd/update.rb
index 33c7c49ae0..200f039792 100644
--- a/Library/Homebrew/cmd/update.rb
+++ b/Library/Homebrew/cmd/update.rb
@@ -56,7 +56,7 @@ module Homebrew
       tap_user, tap_repo = migration.split "/"
       install_tap tap_user, tap_repo
       # update tap for each Tab
-      tabs = dir.subdirs.each.map { |d| Tab.for_keg(Keg.new(d)) }
+      tabs = dir.subdirs.map { |d| Tab.for_keg(Keg.new(d)) }
       next if tabs.first.source["tap"] != "Homebrew/homebrew"
       tabs.each { |tab| tab.source["tap"] = "#{tap_user}/homebrew-#{tap_repo}" }
       tabs.each(&:write)