diff --git a/Library/Homebrew/cmd/tap.rb b/Library/Homebrew/cmd/tap.rb
index b728373206..16ed0a9a8c 100644
--- a/Library/Homebrew/cmd/tap.rb
+++ b/Library/Homebrew/cmd/tap.rb
@@ -14,12 +14,17 @@ module Homebrew extend self
   def install_tap user, repo
     raise "brew install git" unless system "/usr/bin/which -s git"
 
-    tapd = HOMEBREW_LIBRARY/"Taps/#{user}-#{repo}"
+    # we special case homebrew so users don't have to shift in a terminal
+    repouser = if user == "homebrew" then "Homebrew" else user end
+    user = "homebrew" if user == "Homebrew"
+
+    # we downcase to avoid case-insensitive filesystem issues
+    tapd = HOMEBREW_LIBRARY/"Taps/#{user.downcase}-#{repo.downcase}"
     raise "Already tapped!" if tapd.directory?
-    abort unless system "git clone https://github.com/#{user}/homebrew-#{repo} #{tapd}"
+    abort unless system "git clone https://github.com/#{repouser}/homebrew-#{repo} #{tapd}"
 
     files = []
-    tapd.find_formula{ |file| files << Pathname.new("#{user}-#{repo}").join(file) }
+    tapd.find_formula{ |file| files << tapd.basename.join(file) }
     tapped = link_tap_formula(files)
     puts "Tapped #{tapped} formula"
   end
diff --git a/Library/Homebrew/cmd/untap.rb b/Library/Homebrew/cmd/untap.rb
index 577a59a12a..e1529c2884 100644
--- a/Library/Homebrew/cmd/untap.rb
+++ b/Library/Homebrew/cmd/untap.rb
@@ -3,6 +3,14 @@ require 'cmd/tap' # for tap_args
 module Homebrew extend self
   def untap
     user, repo = tap_args
+
+    # we consistently downcase in tap to ensure we are not bitten by case-insensive
+    # filesystem issues. Which is the default on mac. The problem being the
+    # filesystem cares, but our regexps don't. So unless we resolve *every* path
+    # we will get bitten.
+    user.downcase!
+    repo.downcase!
+
     tapd = HOMEBREW_LIBRARY/"Taps/#{user}-#{repo}"
 
     raise "No such tap!" unless tapd.directory?