diff --git a/main/install/ajax.php b/main/install/ajax.php
index d17c8dd98c..70f0f5fc4c 100644
--- a/main/install/ajax.php
+++ b/main/install/ajax.php
@@ -46,7 +46,7 @@ if ($installType === 'new') {
     $dbName = null;
 }
 
-$dbPort = isset($_POST['db_port']) ? $_POST['db_port'] : 3306;
+$dbPort = isset($_POST['db_port']) ? (int) $_POST['db_port'] : 3306;
 
 $manager = connectToDatabase($dbHost, $dbUsername, $dbPass, $dbName, $dbPort);
 
diff --git a/main/install/index.php b/main/install/index.php
index 4f0c168cb8..727cca8c4d 100755
--- a/main/install/index.php
+++ b/main/install/index.php
@@ -279,6 +279,7 @@ if (!isset($_GET['running'])) {
         $GLOBALS[$key] = $_POST[$key];
     }
 }
+$dbPortForm = (int) $dbPortForm;
 
 /* NEXT STEPS IMPLEMENTATION */