diff --git a/README.md b/README.md
index d8bab15..b352208 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ Use [API documentation](http://retailcrm.github.io/api-client-php)
 
 2) Run into your project directory:
 ```bash
-composer require retailcrm/api-client-php ~4.0.0 --no-dev
+composer require retailcrm/api-client-php 4.* --no-dev
 ```
 
 If you have not used `composer` before, include autoloader into your project.
diff --git a/README.ru.md b/README.ru.md
index 369d52f..c262ab0 100644
--- a/README.ru.md
+++ b/README.ru.md
@@ -15,7 +15,7 @@ PHP-клиент для работы с [retailCRM API](http://www.retailcrm.ru/
 
 2) Выполните в папке проекта:
 ```bash
-composer require retailcrm/api-client-php ~4.0.0  --no-dev
+composer require retailcrm/api-client-php 4.*  --no-dev
 ```
 
 В конфиг `composer.json` вашего проекта будет добавлена библиотека `retailcrm/api-client-php`, которая установится в папку `vendor/`. При отсутствии файла конфига или папки с вендорами они будут созданы.
diff --git a/composer.json b/composer.json
index 90f4b93..8fa0434 100644
--- a/composer.json
+++ b/composer.json
@@ -16,6 +16,9 @@
         "ext-curl": "*",
         "phpunit/phpunit": "4.8.29"
     },
+    "require-dev": {
+        "phpunit/phpunit": "4.8.29"
+    },
     "support": {
         "email": "support@retailcrm.pro"
     },
diff --git a/lib/RetailCrm/Response/ApiResponse.php b/lib/RetailCrm/Response/ApiResponse.php
index 6959f2c..03ecb82 100644
--- a/lib/RetailCrm/Response/ApiResponse.php
+++ b/lib/RetailCrm/Response/ApiResponse.php
@@ -121,6 +121,18 @@ class ApiResponse implements \ArrayAccess
         return $this->response[$name];
     }
 
+    /**
+     * Allow to check if the property exists through object property
+     *
+     * @param string $name property name
+     *
+     * @return bool
+     */
+    public function __isset($name)
+    {
+        return isset($this->response[$name]);
+    }
+
     /**
      * Offset set
      *
diff --git a/tests/RetailCrm/Tests/ApiClientOrdersTest.php b/tests/RetailCrm/Tests/ApiClientOrdersTest.php
index e844bf6..2345a0a 100644
--- a/tests/RetailCrm/Tests/ApiClientOrdersTest.php
+++ b/tests/RetailCrm/Tests/ApiClientOrdersTest.php
@@ -241,7 +241,7 @@ class ApiClientOrdersTest extends TestCase
 
     /**
      * @group orders
-]     */
+     */
     public function testOrdersFixExternalIds()
     {
         $client = static::getApiClient();
diff --git a/tests/RetailCrm/Tests/Response/ApiResponseTest.php b/tests/RetailCrm/Tests/Response/ApiResponseTest.php
index 470fd17..43e9f1b 100644
--- a/tests/RetailCrm/Tests/Response/ApiResponseTest.php
+++ b/tests/RetailCrm/Tests/Response/ApiResponseTest.php
@@ -251,4 +251,22 @@ class ApiResponseTest extends TestCase
         $response = new ApiResponse(201, '{ "success": true }');
         unset($response['sssssssuccess']);
     }
+
+    /**
+     * @group unit
+     */
+    public function testMagicIsset()
+    {
+        $response = new ApiResponse(201, '{ "success": true }');
+
+        $this->assertTrue(
+            isset($response->success),
+            'Response object returns property existing'
+        );
+
+        $this->assertFalse(
+            isset($response->suess),
+            'Response object returns property existing'
+        );
+    }
 }