diff --git a/lib/common.lib.php b/lib/common.lib.php
index da968e569..51185f61e 100644
--- a/lib/common.lib.php
+++ b/lib/common.lib.php
@@ -773,7 +773,8 @@ function get_member($mb_id, $fields='*', $is_cache=false)
 {
     global $g5;
     
-    $mb_id = preg_replace("/[^0-9a-z_]+/i", "", $mb_id);
+    if (preg_match("/[^0-9a-z_]+/i", $mb_id))
+        return array();
 
     static $cache = array();