diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a115da..ca0c818 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
-## 2.7.1 - TBD
+## 2.8.0 - TBD
 
 ### Added
 
@@ -25,6 +25,25 @@ All notable changes to this project will be documented in this file, in reverse
 - [#23](https://github.com/zendframework/zend-captcha/pull/23) fixes an issue with garbage collection of expired CAPTCHA images
   when concurrent requests trigger collection.
 
+## 2.7.1 - TBD
+
+### Added
+
+- Nothing.
+
+### Deprecated
+
+- Nothing.
+
+### Removed
+
+- Nothing.
+
+### Fixed
+
+- [#31](https://github.com/zendframework/zend-captcha/pull/31) fixes using the
+  ReCaptcha response as the value parameter to isValid().
+
 ## 2.7.0 - 2017-02-20
 
 ### Added
diff --git a/README.md b/README.md
index 006e7dc..f1c59b6 100644
--- a/README.md
+++ b/README.md
@@ -11,4 +11,4 @@ submissions where authenticated users are not necessary, but you want to prevent
 spam submissions.
 
 - File issues at https://github.com/zendframework/zend-captcha/issues
-- Documentation is at https://zendframework.github.io/zend-captcha/
+- Documentation is at https://docs.zendframework.com/zend-captcha/
diff --git a/doc/book/usage.md b/doc/book/usage.md
index d787906..08c71c9 100644
--- a/doc/book/usage.md
+++ b/doc/book/usage.md
@@ -44,5 +44,5 @@ you will use the combination of:
 >
 > [zend-form](https://github.com/zendframework/zend-form) contains integration
 > with zend-captcha via the class `Zend\Form\Element\Captcha`; read the
-> [documentation on the CAPTCHA form element](http://framework.zend.com/manual/current/en/modules/zend.form.elements.html#captcha)
+> [documentation on the CAPTCHA form element](https://docs.zendframework.com/zend-form/element/captcha/)
 > for more details.
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 73980df..2b314b3 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -27,6 +27,11 @@
         <!-- Enable this if you have installed ZendService\ReCaptcha on the
              include_path or via Composer. -->
         <env name="TESTS_ZEND_CAPTCHA_RECAPTCHA_SUPPORT" value="false" />
+        <!-- Change these if you want to use your own keys -->
+        <!-- These are test keys. See: https://developers.google.com/recaptcha/docs/faq -->
+        <env name="TESTS_ZEND_SERVICE_RECAPTCHA_SITE_KEY" value="6LeIxAcTAAAAAJcZVRqyHh71UMIEGNQ_MXjiZKhI"/>
+        <env name="TESTS_ZEND_SERVICE_RECAPTCHA_SECRET_KEY" value="6LeIxAcTAAAAAGG-vFI1TnRWxMZNFuojJ4WifJWe"/>
+        <env name="TESTS_ZEND_SERVICE_RECAPTCHA_RESPONSE" value="03AI-r6f4PlCfbU_-3HGwscafLbnxjinCf7GKEErJlUHDVF1uJ_SoVebG8gJewkGjNTwLxMZNQPJ4XRTvovB8J6vHLHCVZ1yV_KzJc1Mca6QVZ_6MsNJxYsXa-5NUWTHRvl7XGkju_oPTlxRNDC7DPPkd3eaav0HW1SfdJY1uRd_w5Fkin7KBXz-Eg8oQRSRQ-MplJacQQ3rlKkpEssu1seliTNNidAmuuHWksZwdVAi4ZMyT52BA98_KitLVipT7yiqSka2m8oJZMa9uYb2buNR7X3qnqsJfUc9BxT5lF2HLiX79STktdSAI"/>
 
         <!-- Enable this to test GC operations. These often fail in parallel
              build environments. -->
diff --git a/src/ReCaptcha.php b/src/ReCaptcha.php
index 722fcf3..cbfbac7 100644
--- a/src/ReCaptcha.php
+++ b/src/ReCaptcha.php
@@ -260,8 +260,12 @@ public function isValid($value, $context = null)
         }
 
         $service = $this->getService();
+        if ((is_string($value) || is_int($value)) && array_key_exists($value, $context)) {
+            $res = $service->verify($context[$value]);
+        } else {
+            $res = $service->verify($value);
+        }
 
-        $res = $service->verify($context[$value]);
         if (! $res) {
             $this->error(self::ERR_CAPTCHA);
             return false;
diff --git a/test/ReCaptchaTest.php b/test/ReCaptchaTest.php
index 7ec57c8..c51e89d 100644
--- a/test/ReCaptchaTest.php
+++ b/test/ReCaptchaTest.php
@@ -10,6 +10,8 @@
 namespace ZendTest\Captcha;
 
 use Zend\Captcha\ReCaptcha;
+use Zend\Http\Client as HttpClient;
+use Zend\Http\Client\Adapter\Socket;
 use ZendService\ReCaptcha\ReCaptcha as ReCaptchaService;
 
 /**
@@ -26,16 +28,8 @@ class ReCaptchaTest extends \PHPUnit_Framework_TestCase
     public function setUp()
     {
         if (! getenv('TESTS_ZEND_CAPTCHA_RECAPTCHA_SUPPORT')) {
-            $this->markTestSkipped('Enable TESTS_ZEND_CAPTCHA_RECAPTCHA_SUPPORT to test PDF render');
+            $this->markTestSkipped('Enable TESTS_ZEND_CAPTCHA_RECAPTCHA_SUPPORT to test Recaptcha');
         }
-
-        if (isset($this->word)) {
-            unset($this->word);
-        }
-
-        $this->captcha = new ReCaptcha([
-            'sessionClass' => 'ZendTest\Captcha\TestAsset\SessionContainer'
-        ]);
     }
 
     public function testConstructorShouldSetOptions()
@@ -163,4 +157,52 @@ public function testUsesReCaptchaHelper()
         $captcha = new ReCaptcha;
         $this->assertEquals('captcha/recaptcha', $captcha->getHelperName());
     }
+
+    public function testValidationForDifferentElementName()
+    {
+        $captcha = new ReCaptcha([
+            'site_key' => getenv('TESTS_ZEND_SERVICE_RECAPTCHA_SITE_KEY'),
+            'secret_key' => getenv('TESTS_ZEND_SERVICE_RECAPTCHA_SECRET_KEY'),
+        ]);
+        $service = $captcha->getService();
+        $service->setIp('127.0.0.1');
+        $service->setHttpClient($this->getHttpClient());
+
+        $response = getenv('TESTS_ZEND_SERVICE_RECAPTCHA_RESPONSE');
+        $value = 'g-recaptcha-response';
+        $context = ['g-recaptcha-response' => getenv('TESTS_ZEND_SERVICE_RECAPTCHA_RESPONSE')];
+
+        $this->assertTrue($captcha->isValid($value, $context));
+    }
+
+    public function testValidationForResponseElementName()
+    {
+        $captcha = new ReCaptcha([
+            'site_key' => getenv('TESTS_ZEND_SERVICE_RECAPTCHA_SITE_KEY'),
+            'secret_key' => getenv('TESTS_ZEND_SERVICE_RECAPTCHA_SECRET_KEY'),
+        ]);
+        $service = $captcha->getService();
+        $service->setIp('127.0.0.1');
+        $service->setHttpClient($this->getHttpClient());
+
+        $response = getenv('TESTS_ZEND_SERVICE_RECAPTCHA_RESPONSE');
+        $value = getenv('TESTS_ZEND_SERVICE_RECAPTCHA_RESPONSE');
+        $context = ['g-recaptcha-response' => getenv('TESTS_ZEND_SERVICE_RECAPTCHA_RESPONSE')];
+
+        $this->assertTrue($captcha->isValid($value, $context));
+    }
+
+    /**
+     * @return HttpClient
+     */
+    private function getHttpClient()
+    {
+        $socket = new Socket();
+        $socket->setOptions([
+            'ssltransport' => 'tls',
+        ]);
+        return new HttpClient(null, [
+            'adapter' => $socket,
+        ]);
+    }
 }