diff --git a/src/JWTOptions.php b/src/JWTOptions.php
index df36dad..c4659a5 100644
--- a/src/JWTOptions.php
+++ b/src/JWTOptions.php
@@ -9,7 +9,7 @@ class JWTOptions
     /**
      *      @var array
      */
-    protected $jwt=array(
+    protected $jwt = array(
         'using'         => false,
         'UAPAY_pubkey'  => '',
         'our_privkey'   => '',
@@ -25,30 +25,44 @@ public function __construct($options)
     {
         if (isset($options['jwt']))
         {
-            // using
-            if ( ! isset($options['jwt']['using']))
-            {
-                throw new Exception\Data('parameter jwt/using is not specified');
-            }
-            if ( ! is_bool($options['jwt']['using']))
-            {
-                throw new Exception\Data('parameter jwt/using is incorrect');
-            }
-            // using
-            if ( ! isset($options['jwt']['UAPAY_pubkey']))
-            {
-                throw new Exception\Data('parameter jwt/UAPAY_pubkey is not specified');
-            }
-            // using
-            if ( ! isset($options['jwt']['our_privkey']))
-            {
-                throw new Exception\Data('parameter jwt/our_privkey is not specified');
-            }
+            $this->is_valid_using($options);
+            $this->is_present_option($options, 'UAPAY_pubkey');
+            $this->is_present_option($options, 'our_privkey');
 
             $this->jwt = $options['jwt'];
         }
     }
 
+    /**
+     *      Check is valid 'using' option
+     *
+     *      @param array $options
+     *      @throws Exception\Data
+     */
+    protected function is_valid_using($options)
+    {
+        $this->is_present_option($options, 'using');
+        if ( ! is_bool($options['jwt']['using']))
+        {
+            throw new Exception\Data('parameter jwt/using is incorrect');
+        }
+    }
+
+    /**
+     *      Check is present option
+     *
+     *      @param array $options
+     *      @param string $name
+     *      @throws Exception\Data
+     */
+    protected function is_present_option($options, $name)
+    {
+        if ( ! isset($options['jwt'][$name]))
+        {
+            throw new Exception\Data('parameter jwt/'.$name.' is not specified');
+        }
+    }
+
     /**
      *      Get jwt options
      *
diff --git a/test/JWTOptionsTest.php b/test/JWTOptionsTest.php
index c96cd1f..d79fc7b 100644
--- a/test/JWTOptionsTest.php
+++ b/test/JWTOptionsTest.php
@@ -54,6 +54,58 @@ public function test_constructor_no_jwt_our_privkey()
         $jo = new JWTOptions(array('api_uri'=>'localhost', 'jwt'=>array('using'=>true, 'UAPAY_pubkey'=>'')));
     }
 
+    public function test_is_valid_using()
+    {
+        $options = array(
+            'api_uri'=>'localhost',
+            'jwt'=>array('using'=>true, 'UAPAY_pubkey'=>'public', 'our_privkey'=>'private')
+        );
+        $jo = new JWTOptions($options);
+        $payload = $this->invokeMethod($jo, 'is_valid_using', array($options));
+    }
+
+    /**
+     * @expectedException UAPAY\Exception\Data
+     * @expectedExceptionMessage parameter jwt/using is incorrect
+     */
+    public function test_is_valid_using_bad_type()
+    {
+        $options = array(
+            'api_uri'=>'localhost',
+            'jwt'=>array('using'=>true, 'UAPAY_pubkey'=>'public', 'our_privkey'=>'private')
+        );
+        $jo = new JWTOptions($options);
+
+        $options['jwt']['using'] = 1234;
+        $payload = $this->invokeMethod($jo, 'is_valid_using', array($options));
+    }
+
+    public function test_is_present_option()
+    {
+        $options = array(
+            'api_uri'=>'localhost',
+            'jwt'=>array('using'=>true, 'UAPAY_pubkey'=>'public', 'our_privkey'=>'private')
+        );
+        $jo = new JWTOptions($options);
+        $payload = $this->invokeMethod($jo, 'is_present_option', array($options, 'our_privkey'));
+    }
+
+    /**
+     * @expectedException UAPAY\Exception\Data
+     * @expectedExceptionMessage parameter jwt/our_privkey is not specified
+     */
+    public function test_is_present_option_not_present()
+    {
+        $options = array(
+            'api_uri'=>'localhost',
+            'jwt'=>array('using'=>true, 'UAPAY_pubkey'=>'public', 'our_privkey'=>'private')
+        );
+        $jo = new JWTOptions($options);
+
+        unset($options['jwt']['our_privkey']);
+        $payload = $this->invokeMethod($jo, 'is_present_option', array($options, 'our_privkey'));
+    }
+
     public function test_get()
     {
         $jo = new JWTOptions(array(