diff --git a/usr/local/www/system_usermanager_settings.php b/usr/local/www/system_usermanager_settings.php
index 0e0b6127b9..c82c47df6f 100755
--- a/usr/local/www/system_usermanager_settings.php
+++ b/usr/local/www/system_usermanager_settings.php
@@ -78,7 +78,7 @@ if ($_POST) {
 	if (!$input_errors) {
 
 		if($_POST['session_timeout'])
-			$pconfig['session_timeout'] = $_POST['session_timeout'];
+			$pconfig['session_timeout'] = intval($_POST['session_timeout']);
 		else
 			unset($config['system']['webgui']['session_timeout']);
 
@@ -360,4 +360,4 @@ if(!$pconfig['backend'])
 	                return true;
 	        }
 	}
-</script>
\ No newline at end of file
+</script>