diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 6516db0..44b14d9 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -1791,7 +1791,7 @@ function watchdog($type, $message, $variables = array(), $severity = WATCHDOG_NO
  * @see theme_status_messages()
  */
 function drupal_set_message($message = NULL, $type = 'status', $repeat = TRUE) {
-  if ($message) {
+  if ($message || $message === '0' || $message === 0) {
     if (!isset($_SESSION['messages'][$type])) {
       $_SESSION['messages'][$type] = array();
     }