diff --git a/Formula/valgrind.rb b/Formula/valgrind.rb
index 6331f6d9682..895db6b68f4 100644
--- a/Formula/valgrind.rb
+++ b/Formula/valgrind.rb
@@ -1,20 +1,43 @@
 require 'formula'
 
+class Autoconf267 <Formula
+  url 'http://ftp.gnu.org/gnu/autoconf/autoconf-2.67.tar.bz2'
+  md5 '3fbf92eb8eaca1e0d33dff9710edb5f0'
+  homepage 'http://www.gnu.org/software/autoconf/'
+end
+
 class Valgrind <Formula
-  url 'http://www.valgrind.org/downloads/valgrind-3.5.0.tar.bz2'
   homepage 'http://www.valgrind.org/'
-  md5 'f03522a4687cf76c676c9494fcc0a517'
+
+  # Stable release doesn't work in 64-bit mode
+  if MACOS_VERSION == 10.5
+    url 'http://www.valgrind.org/downloads/valgrind-3.5.0.tar.bz2'
+    md5 'f03522a4687cf76c676c9494fcc0a517'
+  end
+
+  head "svn://svn.valgrind.org/valgrind/trunk", :revision => "11255"
+
+  depends_on 'pkg-config'
+  depends_on 'boost'
 
   def install
-    opoo "Valgrind 3.5.0 doesn't support Snow Leopard; see caveats." if MACOS_VERSION > 10.5
-    system "./configure", "--prefix=#{prefix}", "--mandir=#{man}"
+    args = ["--prefix=#{prefix}", "--mandir=#{man}"]
+
+    if MACOS_VERSION >= 10.6
+      # OS X comes with 2.61, which is too old
+      ac_prefix = Pathname.pwd+'ac267'
+      Autoconf267.new.brew do |f|
+        system "./configure", "--prefix=#{ac_prefix}"
+        system "make install"
+      end
+
+      ENV.prepend "PATH", ac_prefix+'bin', ":"
+
+      system "./autogen.sh" if File.exists? "autogen.sh"
+      args << "--enable-only64bit" << "--build=amd64-darwin"
+    end
+
+    system "./configure", *args
     system "make install"
   end
-
-  def caveats
-    if MACOS_VERSION > 10.5
-      "Valgrind does not work on Snow Leopard / 64-bit mode. See:\n"+
-      "    http://bugs.kde.org/show_bug.cgi?id=205241"
-    end
-  end
 end