diff --git a/spec/EcPhp/CasLib/CasSpec.php b/spec/EcPhp/CasLib/CasSpec.php
index e53b269..1d1daf4 100644
--- a/spec/EcPhp/CasLib/CasSpec.php
+++ b/spec/EcPhp/CasLib/CasSpec.php
@@ -131,7 +131,14 @@ public function it_can_authenticate_a_request(ClientInterface $client, CacheItem
 
         $this
             ->authenticate($request)
-            ->shouldBeArray();
+            ->shouldBeEqualTo([
+                'serviceResponse' => [
+                    'authenticationSuccess' => [
+                        'user' => 'username',
+                        'proxyGrantingTicket' => 'pgtId',
+                    ],
+                ],
+            ]);
 
         $request = new ServerRequest('GET', UtilsUri::withParams(new Uri('http://from'), ['ticket' => 'ST-ticket-pgt-pgtiou-not-found']));
 
diff --git a/spec/EcPhp/CasLib/Response/Type/ProxyFailureSpec.php b/spec/EcPhp/CasLib/Response/Type/ProxyFailureSpec.php
index cf4c81f..5f26564 100644
--- a/spec/EcPhp/CasLib/Response/Type/ProxyFailureSpec.php
+++ b/spec/EcPhp/CasLib/Response/Type/ProxyFailureSpec.php
@@ -9,7 +9,7 @@
 
 declare(strict_types=1);
 
-namespace spec\EcPhp\CasLib\Introspection;
+namespace spec\EcPhp\CasLib\Response\Type;
 
 use Nyholm\Psr7\Response;
 use PhpSpec\ObjectBehavior;
@@ -18,7 +18,19 @@ class ProxyFailureSpec extends ObjectBehavior
 {
     public function it_can_detect_a_proxy_failure_response()
     {
-        $response = (new Response(200));
+        $body = [
+            'serviceResponse' => [
+                'proxyFailure' => "unrecognized pgt: 'PGT-123'",
+            ],
+        ];
+
+        $response = new Response(
+            200,
+            [
+                'Content-Type' => 'application/json',
+            ],
+            json_encode($body)
+        );
 
         $parsed = [
             'serviceResponse' => [
@@ -27,14 +39,14 @@ public function it_can_detect_a_proxy_failure_response()
         ];
 
         $this
-            ->beConstructedWith($parsed, 'XML', $response);
+            ->beConstructedWith($response);
 
         $this
             ->getMessage()
             ->shouldReturn("unrecognized pgt: 'PGT-123'");
 
         $this
-            ->getResponse()
-            ->shouldReturn($response);
+            ->toArray()
+            ->shouldReturn($parsed);
     }
 }
diff --git a/spec/EcPhp/CasLib/Response/Type/ProxySpec.php b/spec/EcPhp/CasLib/Response/Type/ProxySpec.php
index 230def5..493e321 100644
--- a/spec/EcPhp/CasLib/Response/Type/ProxySpec.php
+++ b/spec/EcPhp/CasLib/Response/Type/ProxySpec.php
@@ -9,7 +9,7 @@
 
 declare(strict_types=1);
 
-namespace spec\EcPhp\CasLib\Introspection;
+namespace spec\EcPhp\CasLib\Response\Type;
 
 use Nyholm\Psr7\Factory\Psr17Factory;
 use Nyholm\Psr7\Response;
@@ -23,11 +23,9 @@ public function it_can_detect_a_proxy_response()
 
         $body = <<< 'EOF'
             <?xml version="1.0" encoding="utf-8"?>
-            <cas:serviceResponse xmlns:cas="https://ecas.ec.europa.eu/cas/schemas"
-                                 server="ECAS MOCKUP version 4.6.0.20924 - 09/02/2016 - 14:37"
-                                 date="2019-10-18T12:17:53.069+02:00" version="4.5">
+            <cas:serviceResponse xmlns:cas="https://ecas.ec.europa.eu/cas/schemas">
             	<cas:proxySuccess>
-            		<cas:proxyTicket>PT-214-A3OoEPNr4Q9kNNuYzmfN8azU31aDUsuW8nk380k7wDExT5PFJpxR1TrNI3q3VGzyDdi0DpZ1LKb8IhPKZKQvavW-8hnfexYjmLCx7qWNsLib1W-DCzzoLVTosAUFzP3XDn5dNzoNtxIXV9KSztF9fYhwHvU0</cas:proxyTicket>
+            		<cas:proxyTicket>PGT-TICKET</cas:proxyTicket>
             	</cas:proxySuccess>
             </cas:serviceResponse>
             EOF;
@@ -39,24 +37,20 @@ public function it_can_detect_a_proxy_response()
         $parsed = [
             'serviceResponse' => [
                 'proxySuccess' => [
-                    'proxyTicket' => 'PT-214-A3OoEPNr4Q9kNNuYzmfN8azU31aDUsuW8nk380k7wDExT5PFJpxR1TrNI3q3VGzyDdi0DpZ1LKb8IhPKZKQvavW-8hnfexYjmLCx7qWNsLib1W-DCzzoLVTosAUFzP3XDn5dNzoNtxIXV9KSztF9fYhwHvU0',
+                    'proxyTicket' => 'PGT-TICKET',
                 ],
             ],
         ];
 
         $this
-            ->beConstructedWith($parsed, 'XML', $response);
+            ->beConstructedWith($response);
 
         $this
             ->getProxyTicket()
-            ->shouldReturn('PT-214-A3OoEPNr4Q9kNNuYzmfN8azU31aDUsuW8nk380k7wDExT5PFJpxR1TrNI3q3VGzyDdi0DpZ1LKb8IhPKZKQvavW-8hnfexYjmLCx7qWNsLib1W-DCzzoLVTosAUFzP3XDn5dNzoNtxIXV9KSztF9fYhwHvU0');
+            ->shouldReturn('PGT-TICKET');
 
         $this
-            ->getFormat()
-            ->shouldReturn('XML');
-
-        $this
-            ->getResponse()
-            ->shouldReturn($response);
+            ->toArray()
+            ->shouldReturn($parsed);
     }
 }
diff --git a/spec/EcPhp/CasLib/Response/Type/ServiceValidateSpec.php b/spec/EcPhp/CasLib/Response/Type/ServiceValidateSpec.php
index 82d0b6c..96e397e 100644
--- a/spec/EcPhp/CasLib/Response/Type/ServiceValidateSpec.php
+++ b/spec/EcPhp/CasLib/Response/Type/ServiceValidateSpec.php
@@ -9,7 +9,7 @@
 
 declare(strict_types=1);
 
-namespace spec\EcPhp\CasLib\Introspection;
+namespace spec\EcPhp\CasLib\Response\Type;
 
 use Nyholm\Psr7\Factory\Psr17Factory;
 use Nyholm\Psr7\Response;
@@ -21,55 +21,45 @@ public function it_can_detect_a_proxy_service_validate_response()
     {
         $psr17Factory = new Psr17Factory();
 
-        $body = <<< 'EOF'
-            Useless stuff here.
-            EOF;
-
-        $response = (new Response(200))
-            ->withHeader('Content-Type', 'application/xml')
-            ->withBody($psr17Factory->createStream($body));
-
-        $credentials = [
-            'user' => 'user',
-            'proxyGrantingTicket' => 'proxyGrantingTicket',
-            'proxies' => [
-                'proxy' => [
-                    'http://proxy1',
-                    'http://proxy2',
-                ],
-            ],
-            'extendedAttributes' => [
-                'extendedAttribute' => [
-                    'attributeValue' => [
-                        0 => 'rex',
-                        1 => 'snoopy',
+        $bodyArray = [
+            'serviceResponse' => [
+                'authenticationSuccess' => [
+                    'user' => 'user',
+                    'proxyGrantingTicket' => 'proxyGrantingTicket',
+                    'proxies' => [
+                        'proxy' => [
+                            'http://proxy1',
+                            'http://proxy2',
+                        ],
                     ],
-                    '@attributes' => [
-                        'name' => 'http://stork.eu/motherInLawDogName',
+                    'extendedAttributes' => [
+                        'extendedAttribute' => [
+                            'attributeValue' => [
+                                0 => 'rex',
+                                1 => 'snoopy',
+                            ],
+                            '@attributes' => [
+                                'name' => 'http://stork.eu/motherInLawDogName',
+                            ],
+                        ],
                     ],
                 ],
             ],
         ];
 
-        $parsed = [
-            'serviceResponse' => [
-                'authenticationSuccess' => $credentials,
-            ],
-        ];
+        $response = (new Response(200))
+            ->withHeader('Content-Type', 'application/json')
+            ->withBody($psr17Factory->createStream(json_encode($bodyArray)));
 
         $this
-            ->beConstructedWith($parsed, 'XML', $response);
+            ->beConstructedWith($response);
 
         $this
             ->getCredentials()
             ->shouldReturn(
-                $credentials
+                $bodyArray['serviceResponse']['authenticationSuccess']
             );
 
-        $this
-            ->getFormat()
-            ->shouldReturn('XML');
-
         $this
             ->getProxies()
             ->shouldReturn([
@@ -80,12 +70,8 @@ public function it_can_detect_a_proxy_service_validate_response()
             ]);
 
         $this
-            ->getResponse()
-            ->shouldReturn($response);
-
-        $this
-            ->getParsedResponse()
-            ->shouldReturn($parsed);
+            ->toArray()
+            ->shouldReturn($bodyArray);
     }
 
     public function it_can_detect_a_service_validate_response()
@@ -105,11 +91,6 @@ public function it_can_detect_a_service_validate_response()
             ->withHeader('Content-Type', 'application/xml')
             ->withBody($psr17Factory->createStream($body));
 
-        $credentials = [
-            'user' => 'user',
-            'proxyGrantingTicket' => 'proxyGrantingTicket',
-        ];
-
         $parsed = [
             'serviceResponse' => [
                 'authenticationSuccess' => [
@@ -120,22 +101,18 @@ public function it_can_detect_a_service_validate_response()
         ];
 
         $this
-            ->beConstructedWith($parsed, 'XML', $response);
-
-        $this
-            ->getCredentials()
-            ->shouldReturn($credentials);
+            ->beConstructedWith($response);
 
         $this
-            ->getFormat()
-            ->shouldReturn('XML');
+            ->toArray()
+            ->shouldReturn($parsed);
 
         $this
             ->getProxies()
             ->shouldReturn([]);
 
         $this
-            ->getResponse()
-            ->shouldReturn($response);
+            ->toArray()
+            ->shouldReturn($parsed);
     }
 }
diff --git a/spec/EcPhp/CasLib/Utils/ResponseSpec.php b/spec/EcPhp/CasLib/Utils/ResponseSpec.php
new file mode 100644
index 0000000..c5b5826
--- /dev/null
+++ b/spec/EcPhp/CasLib/Utils/ResponseSpec.php
@@ -0,0 +1,100 @@
+<?php
+
+/**
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ecphp
+ */
+
+declare(strict_types=1);
+
+namespace spec\EcPhp\CasLib\Utils;
+
+use EcPhp\CasLib\Exception\CasExceptionInterface;
+use Nyholm\Psr7\Response;
+use PhpSpec\ObjectBehavior;
+
+class ResponseSpec extends ObjectBehavior
+{
+    public function it_convert_a_json_response()
+    {
+        $body = <<< 'EOF'
+            {
+                "serviceResponse": {
+                    "authenticationSuccess": {
+                        "user": "username"
+                    }
+                }
+            }
+            EOF;
+
+        $response = new Response(
+            200,
+            [
+                'Content-Type' => 'application/json',
+            ],
+            $body
+        );
+
+        $this
+            ->toArray($response)
+            ->shouldReturn([
+                'serviceResponse' => [
+                    'authenticationSuccess' => [
+                        'user' => 'username',
+                    ],
+                ],
+            ]);
+    }
+
+    public function it_convert_a_xml_response()
+    {
+        $body = <<< 'EOF'
+                <cas:serviceResponse xmlns:cas="http://www.yale.edu/tp/cas">
+                    <cas:authenticationSuccess>
+                        <cas:user>username</cas:user>
+                    </cas:authenticationSuccess>
+                </cas:serviceResponse>
+            EOF;
+
+        $response = new Response(
+            200,
+            [
+                'Content-Type' => 'application/xml',
+            ],
+            $body
+        );
+
+        $this
+            ->toArray($response)
+            ->shouldReturn([
+                'serviceResponse' => [
+                    'authenticationSuccess' => [
+                        'user' => 'username',
+                    ],
+                ],
+            ]);
+    }
+
+    public function it_throws_when_content_type_header_is_missing()
+    {
+        $body = <<< 'EOF'
+                <cas:serviceResponse xmlns:cas="http://www.yale.edu/tp/cas">
+                    <cas:authenticationSuccess>
+                        <cas:user>username</cas:user>
+                    </cas:authenticationSuccess>
+                </cas:serviceResponse>
+            EOF;
+
+        $response = new Response(
+            200,
+            [],
+            $body
+        );
+
+        $this
+            ->shouldThrow(CasExceptionInterface::class)
+            ->during('toArray', [$response]);
+    }
+}