diff --git a/src/js/index.js b/src/js/index.js
index 13974ae38..9073feea5 100644
--- a/src/js/index.js
+++ b/src/js/index.js
@@ -595,11 +595,13 @@ app.directive('tagInput', function () {
                 });
             };
             $scope.addTag = function () {
-                var tagArray;
-                if ($scope.tagText.length === 0) {
-                    return;
+                var tagArray = $scope.tagArray();
+
+                // prevent adding empty or existing items
+                if ($scope.tagText.length === 0 || tagArray.indexOf($scope.tagText) !== -1) {
+                    return $scope.tagText = '';
                 }
-                tagArray = $scope.tagArray();
+
                 tagArray.push($scope.tagText);
                 $scope.inputTags = tagArray.join(',');
                 return $scope.tagText = '';