diff --git a/install_minimal/upgrades/airtime-1.9.0/airtime-upgrade.php b/install_minimal/upgrades/airtime-1.9.0/airtime-upgrade.php
index 7df7f9240..3c28492d9 100644
--- a/install_minimal/upgrades/airtime-1.9.0/airtime-upgrade.php
+++ b/install_minimal/upgrades/airtime-1.9.0/airtime-upgrade.php
@@ -590,7 +590,7 @@ class Airtime190Upgrade{
            ->setFormatter(ModelCriteria::FORMAT_ON_DEMAND)
            ->find();
 
-        $dumpFile = __DIR__"/storDump.txt";
+        $dumpFile = __DIR__."/storDump.txt";
         $fh = fopen($dumpFile, 'w') or die("can't open file to backup stor.");
 
         $s = "SF_BACKUP";