diff --git a/src/directives/stateDirectives.ts b/src/directives/stateDirectives.ts
index f58f2247b..dc4aec52a 100644
--- a/src/directives/stateDirectives.ts
+++ b/src/directives/stateDirectives.ts
@@ -249,10 +249,10 @@ uiSref = ['$uiRouter', '$timeout',
 
         if (ref.paramExpr) {
           scope.$watch(ref.paramExpr, function (val) {
-            rawDef.uiStateParams = angular.copy(val);
+            rawDef.uiStateParams = extend({}, val);
             update();
           }, true);
-          rawDef.uiStateParams = angular.copy(scope.$eval(ref.paramExpr));
+          rawDef.uiStateParams = extend({}, scope.$eval(ref.paramExpr));
         }
 
         update();