diff --git a/src/scripts/directives/setting.js b/src/scripts/directives/setting.js
index 0f21d6b..9ba2d66 100644
--- a/src/scripts/directives/setting.js
+++ b/src/scripts/directives/setting.js
@@ -146,7 +146,7 @@
                         return;
                     }
 
-                    if ((scope.option.type == 'integer' || scope.option.type == 'float') && (!angular.isUndefined(scope.option.min) || !angular.isUndefined(scope.option.max))) {
+                    if ((scope.option.type == 'integer' || scope.option.type == 'float') && (angular.isDefined(scope.option.min) || angular.isDefined(scope.option.max))) {
                         var number = optionValue;
 
                         if (scope.option.type == 'integer') {
@@ -155,18 +155,18 @@
                             number = parseFloat(optionValue);
                         }
 
-                        if (!angular.isUndefined(scope.option.min) && number < scope.option.min) {
+                        if (angular.isDefined(scope.option.min) && number < scope.option.min) {
                             scope.optionStatus.setError('Input number is below min value!', { value: scope.option.min });
                             return;
                         }
 
-                        if (!angular.isUndefined(scope.option.max) && number > scope.option.max) {
+                        if (angular.isDefined(scope.option.max) && number > scope.option.max) {
                             scope.optionStatus.setError('Input number is above max value!', { value: scope.option.max });
                             return;
                         }
                     }
 
-                    if (!angular.isUndefined(scope.option.pattern) && !(new RegExp(scope.option.pattern).test(optionValue))) {
+                    if (angular.isDefined(scope.option.pattern) && !(new RegExp(scope.option.pattern).test(optionValue))) {
                         scope.optionStatus.setError('Input value is invalid!');
                         return;
                     }
diff --git a/src/scripts/services/aria2RpcService.js b/src/scripts/services/aria2RpcService.js
index 46c2ea4..a835e0a 100644
--- a/src/scripts/services/aria2RpcService.js
+++ b/src/scripts/services/aria2RpcService.js
@@ -128,7 +128,7 @@
 
             if (arguments.length > 2) {
                 for (var i = 2; i < arguments.length; i++) {
-                    if (arguments[i] != null && !angular.isUndefined(arguments[i])) {
+                    if (arguments[i] != null && angular.isDefined(arguments[i])) {
                         finalParams.push(arguments[i]);
                     }
                 }
@@ -285,21 +285,21 @@
             },
             tellActive: function (context) {
                 return invoke(buildRequestContext('tellActive', context,
-                    angular.isUndefined(context.requestParams) ? null : context.requestParams
+                    angular.isDefined(context.requestParams) ? context.requestParams: null
                 ));
             },
             tellWaiting: function (context) {
                 return invoke(buildRequestContext('tellWaiting', context,
-                    angular.isUndefined(context.offset) ? 0 : context.offset,
-                    angular.isUndefined(context.num) ? 1000 : context.num,
-                    angular.isUndefined(context.requestParams) ? null : context.requestParams
+                    angular.isDefined(context.offset) ? context.offset : 0,
+                    angular.isDefined(context.num) ? context.num : 1000,
+                    angular.isDefined(context.requestParams) ? context.requestParams : null
                 ));
             },
             tellStopped: function (context) {
                 return invoke(buildRequestContext('tellStopped', context,
-                    angular.isUndefined(context.offset) ? 0 : context.offset,
-                    angular.isUndefined(context.num) ? 1000 : context.num,
-                    angular.isUndefined(context.requestParams) ? null : context.requestParams
+                    angular.isDefined(context.offset) ? context.offset : 0,
+                    angular.isDefined(context.num) ? context.num : 1000,
+                    angular.isDefined(context.requestParams) ? context.requestParams: null
                 ));
             },
             changePosition: function (context) {
diff --git a/src/scripts/services/ariaNgMonitorService.js b/src/scripts/services/ariaNgMonitorService.js
index 8b8d072..8bc167f 100644
--- a/src/scripts/services/ariaNgMonitorService.js
+++ b/src/scripts/services/ariaNgMonitorService.js
@@ -97,7 +97,7 @@
         };
 
         var isStorageExist = function (key) {
-            return !angular.isUndefined(storagesInMemory[key]);
+            return angular.isDefined(storagesInMemory[key]);
         };
 
         var pushToStorage = function (key, stat) {