diff --git a/atf.inc.php b/atf.inc.php
index bd5294b..cbae5bf 100644
--- a/atf.inc.php
+++ b/atf.inc.php
@@ -1298,7 +1298,9 @@ function atf_guid()
 
 function _atf_start_watchdog($guid)
 {
-  $script = dirname(__FILE__) . '/../gamectl atf_watchdog ' . getmypid() . ' ' . $guid;
+  global $GAME_ROOT;
+
+  $script = "$GAME_ROOT/gamectl atf_watchdog " . getmypid() . ' ' . $guid;
   exec("nohup $script > /dev/null &", $output, $ret);
 }