diff --git a/modules/filter/filter.module b/modules/filter/filter.module
index 182033f..67ce252 100644
--- a/modules/filter/filter.module
+++ b/modules/filter/filter.module
@@ -1454,7 +1454,7 @@ function _filter_url($text, $filter) {
   // we cannot cleanly differ between protocols here without hard-coding MAILTO,
   // so '//' is optional for all protocols.
   // @see filter_xss_bad_protocol()
-  $protocols = variable_get('filter_allowed_protocols', array('http', 'https', 'ftp', 'news', 'nntp', 'telnet', 'mailto', 'irc', 'ssh', 'sftp', 'webcal', 'rtsp'));
+  $protocols = variable_get('filter_allowed_protocols', array('ftp', 'http', 'https', 'irc', 'mailto', 'news', 'nntp', 'rtsp', 'sftp', 'ssh', 'tel', 'telnet', 'webcal'));
   $protocols = implode(':(?://)?|', $protocols) . ':(?://)?';
 
   // Prepare domain name pattern.