diff --git a/Library/Homebrew/cmd/update.rb b/Library/Homebrew/cmd/update.rb
index c15dfa042c..8b2d2e3d40 100644
--- a/Library/Homebrew/cmd/update.rb
+++ b/Library/Homebrew/cmd/update.rb
@@ -19,6 +19,8 @@ module Homebrew extend self
 
     new_files = []
     Dir["Library/Taps/*"].each do |tapd|
+      next unless File.directory?(tapd)
+
       cd tapd do
         begin
           updater = Updater.new