diff --git a/include/filter.inc.php b/include/filter.inc.php
index 49e3fb7d4..77f39d960 100644
--- a/include/filter.inc.php
+++ b/include/filter.inc.php
@@ -14,7 +14,7 @@
 	
 	function valid_url($url) {
 		if( preg_match("/\.\./", $url) ) return FALSE;
-		if( ! preg_match("/^[a-zA-Z0-9\._:\/~]*$/", $url) ) return FALSE;
+		if( ! preg_match("/^[\-a-zA-Z0-9\._:\/~]*$/", $url) ) return FALSE;
 		return filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED);
 	}