diff --git a/UrlLinker.php b/UrlLinker.php
index <HASH>..<HASH> 100644
--- a/UrlLinker.php
+++ b/UrlLinker.php
@@ -14,7 +14,7 @@
  *  Regular expression bits used by htmlEscapeAndLinkUrls() to match URLs.

  */

 $rexProtocol  = '(https?://)?';

-$rexDomain    = '(?:[-a-zA-Z0-9]{1,63}\.)+[-a-zA-Z0-9]{2,63}';

+$rexDomain    = '(?:[-a-zA-Z0-9]{1,63}\.)+[a-zA-Z][-a-zA-Z0-9]{1,62}';

 $rexIp        = '(?:[0-9]{1,3}\.){3}[0-9]{1,3}';

 $rexPort      = '(:[0-9]{1,5})?';

 $rexPath      = '(/[!$-/0-9:;=@_\':;!a-zA-Z\x7f-\xff]*?)?';
UrlLinker: : Don't match TLDs that start with a digit.