diff --git a/Library/Homebrew/cmd/cleanup.rb b/Library/Homebrew/cmd/cleanup.rb
index 0f2a1875d3..ba9745f1aa 100644
--- a/Library/Homebrew/cmd/cleanup.rb
+++ b/Library/Homebrew/cmd/cleanup.rb
@@ -50,6 +50,7 @@ module Homebrew extend self
 
   def clean_cache
     HOMEBREW_CACHE.children.each do |pn|
+      next unless pn.file?
       pn.stem =~ /^(.+)-(.+)$/ # greedy so works even if formula-name has hyphens in it
       if $1 and $2
         f = Formula.factory($1) rescue nil