diff --git a/src/datepickerPopup/popup.js b/src/datepickerPopup/popup.js
index 02c0e88a1c..6baa936a49 100644
--- a/src/datepickerPopup/popup.js
+++ b/src/datepickerPopup/popup.js
@@ -301,7 +301,7 @@ function($scope, $element, $attrs, $compile, $log, $parse, $window, $document, $
 
   function parseDateString(viewValue) {
     var date = dateParser.parse(viewValue, dateFormat, $scope.date);
-    if (isNaN(date)) {
+    if (isNaN(date) && angular.isArray(altInputFormats)) {
       for (var i = 0; i < altInputFormats.length; i++) {
         date = dateParser.parse(viewValue, altInputFormats[i], $scope.date);
         if (!isNaN(date)) {