diff --git a/src/sortable.js b/src/sortable.js
index 7c39e53..409aa65 100644
--- a/src/sortable.js
+++ b/src/sortable.js
@@ -8,9 +8,11 @@ angular.module('ui.sortable', []).value('uiSortableConfig',{}).directive('uiSort
     return {
       require: '?ngModel',
       link: function(scope, element, attrs, ngModel) {
-        var onReceive, onRemove, onStart, onStop, onUpdate, opts;
+        var onReceive, onRemove, onStart, onStop, onUpdate, opts = {};
 
-        opts = angular.extend({}, uiSortableConfig, scope.$eval(attrs.uiSortable));
+        attrs.$observe('ui-sortable', function(){
+          opts = angular.extend({}, uiSortableConfig, scope.$eval(attrs.uiSortable));
+        });
 
         if (ngModel) {