diff --git a/fn/ht.php b/fn/ht.php
index 27f5a59..42b99d1 100644
--- a/fn/ht.php
+++ b/fn/ht.php
@@ -16,7 +16,7 @@ function listFsDirs($username) {
 	$absoluteDirs = glob(CONF['ht']['ht_path'] . "/" . $username . "/*/", GLOB_ONLYDIR);
 	$dirs = [];
 	foreach ($absoluteDirs as $absoluteDir)
-		if (preg_match("/^[\p{L}\p{N}_-]+$/u", basename($absoluteDir)))
+		if (preg_match('/^[\p{L}\p{N}_-]{1,64}$/u', basename($absoluteDir)))
 			array_push($dirs, basename($absoluteDir));
 	return $dirs;
 }