diff --git a/Library/Homebrew/brewkit.rb b/Library/Homebrew/brewkit.rb
index 95243810c9..6786552743 100644
--- a/Library/Homebrew/brewkit.rb
+++ b/Library/Homebrew/brewkit.rb
@@ -70,7 +70,7 @@ def extract_version basename
   return $1 if $1
 
   # eg. foobar-4.5.1b
-  /-((\d+\.)*\d+[abc])$/.match basename
+  /-((\d+\.)*\d+([abc]|rc\d))$/.match basename
   return $1 if $1
   
   # eg. foobar4.5.1
diff --git a/Library/Homebrew/unittest.rb b/Library/Homebrew/unittest.rb
index da2fedb88d..68856baefd 100755
--- a/Library/Homebrew/unittest.rb
+++ b/Library/Homebrew/unittest.rb
@@ -47,6 +47,11 @@ class BeerTasting <Test::Unit::TestCase
     assert_equal '1.23', r.version
   end
   
+  def test_version_libvorbis
+    r=TestFormula.new "http://downloads.xiph.org/releases/vorbis/libvorbis-1.2.2rc1.tar.bz2"
+    assert_equal '1.2.2rc1', r.version
+  end
+  
   def test_dos2unix
     r=TestFormula.new "http://www.sfr-fresh.com/linux/misc/dos2unix-3.1.tar.gz"
     assert_equal '3.1', r.version