diff --git a/Library/Homebrew/cmd/cleanup.rb b/Library/Homebrew/cmd/cleanup.rb
index 6c3b9ffbf7..9a211dcbc1 100644
--- a/Library/Homebrew/cmd/cleanup.rb
+++ b/Library/Homebrew/cmd/cleanup.rb
@@ -31,8 +31,7 @@ module Homebrew
   end
 
   def cleanup_cellar
-    return unless HOMEBREW_CELLAR.directory?
-    HOMEBREW_CELLAR.subdirs.each do |rack|
+    Formula.racks.each do |rack|
       begin
         cleanup_formula Formulary.from_rack(rack)
       rescue FormulaUnavailableError, TapFormulaAmbiguityError
diff --git a/Library/Homebrew/cmd/info.rb b/Library/Homebrew/cmd/info.rb
index 854344bd41..21c04ed46f 100644
--- a/Library/Homebrew/cmd/info.rb
+++ b/Library/Homebrew/cmd/info.rb
@@ -22,7 +22,7 @@ module Homebrew
   def print_info
     if ARGV.named.empty?
       if HOMEBREW_CELLAR.exist?
-        count = HOMEBREW_CELLAR.subdirs.length
+        count = Formula.racks.length
         puts "#{count} keg#{plural(count)}, #{HOMEBREW_CELLAR.abv}"
       end
     else
diff --git a/Library/Homebrew/cmd/linkapps.rb b/Library/Homebrew/cmd/linkapps.rb
index f484d98508..9a58bd37a9 100644
--- a/Library/Homebrew/cmd/linkapps.rb
+++ b/Library/Homebrew/cmd/linkapps.rb
@@ -1,5 +1,6 @@
 # Links any Applications (.app) found in installed prefixes to /Applications
 require "keg"
+require "formula"
 
 module Homebrew
   def linkapps
@@ -12,8 +13,7 @@ module Homebrew
     end
 
     if ARGV.named.empty?
-      racks = HOMEBREW_CELLAR.subdirs
-      kegs = racks.map do |rack|
+      kegs = Formula.racks.map do |rack|
         keg = rack.subdirs.map { |d| Keg.new(d) }
         next if keg.empty?
         keg.detect(&:linked?) || keg.max { |a, b| a.version <=> b.version }
diff --git a/Library/Homebrew/cmd/list.rb b/Library/Homebrew/cmd/list.rb
index cdb0e68599..b35b0e3891 100644
--- a/Library/Homebrew/cmd/list.rb
+++ b/Library/Homebrew/cmd/list.rb
@@ -78,7 +78,7 @@ module Homebrew
 
   def filtered_list
     names = if ARGV.named.empty?
-      HOMEBREW_CELLAR.subdirs
+      Formula.racks
     else
       ARGV.named.map { |n| HOMEBREW_CELLAR+n }.select(&:exist?)
     end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 7aa44c44f2..c457dbc02b 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -809,20 +809,25 @@ class Formula
     end
   end
 
-  # An array of all installed {Formula}
-  def self.installed
-    @installed ||= if HOMEBREW_CELLAR.directory?
-      HOMEBREW_CELLAR.subdirs.map do |rack|
-        begin
-          Formulary.from_rack(rack)
-        rescue FormulaUnavailableError, TapFormulaAmbiguityError
-        end
-      end.compact
+  # An array of all racks currently installed.
+  def self.racks
+    @racks ||= if HOMEBREW_CELLAR.directory?
+      HOMEBREW_CELLAR.subdirs.reject(&:symlink?)
     else
       []
     end
   end
 
+  # An array of all installed {Formula}
+  def self.installed
+    @installed ||= racks.map do |rack|
+      begin
+        Formulary.from_rack(rack)
+      rescue FormulaUnavailableError, TapFormulaAmbiguityError
+      end
+    end.compact
+  end
+
   def self.aliases
     Dir["#{HOMEBREW_LIBRARY}/Aliases/*"].map { |f| File.basename f }.sort
   end