diff --git a/UI/WebServerResources/js/PreferencesUI.js b/UI/WebServerResources/js/PreferencesUI.js
index 7ef5a3aa1..1ff7cf9ac 100644
--- a/UI/WebServerResources/js/PreferencesUI.js
+++ b/UI/WebServerResources/js/PreferencesUI.js
@@ -134,6 +134,9 @@
       };
 
       $scope.addMailFilter = function(ev) {
+        if (!$scope.preferences.defaults.SOGoSieveFilters)
+          $scope.preferences.defaults.SOGoSieveFilters = [];
+
         $scope.preferences.defaults.SOGoSieveFilters.push({});
         var filter = _.last($scope.preferences.defaults.SOGoSieveFilters);
         $mdDialog.show({