diff --git a/phpunit.xml b/phpunit.xml
index e89ac6d..3fd23bc 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -10,9 +10,14 @@
          stopOnFailure="false"
          syntaxCheck="false"
 >
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">./src</directory>
+        </whitelist>
+    </filter>
     <testsuites>
         <testsuite name="Package Test Suite">
             <directory suffix=".php">./tests/</directory>
         </testsuite>
     </testsuites>
-</phpunit>
\ No newline at end of file
+</phpunit>
diff --git a/src/Provider/Mollie.php b/src/Provider/Mollie.php
index ff7de14..daf21ab 100644
--- a/src/Provider/Mollie.php
+++ b/src/Provider/Mollie.php
@@ -63,15 +63,51 @@ class Mollie extends AbstractProvider
 	const SCOPE_ONBOARDING_READ     = 'onboarding.read';
 	const SCOPE_ONBOARDING_WRITE    = 'onboarding.write';
 
+    /**
+     * @var string
+     */
+    private $mollieApiUrl = self::MOLLIE_API_URL;
+
+    /**
+     * @var string
+     */
+    private $mollieWebUrl = self::MOLLIE_WEB_URL;
+
 	public function __construct(array $options = [], array $collaborators = [])
 	{
-		parent::__construct($options, $collaborators);
+        parent::__construct($options, $collaborators);
 
 		if (isset($options["clientId"]) && strpos($options["clientId"], self::CLIENT_ID_PREFIX) !== 0) {
 			throw new \DomainException("Mollie needs the client ID to be prefixed with " . self::CLIENT_ID_PREFIX . ".");
 		}
 	}
 
+    /**
+     * Define Mollie api URL
+     *
+     * @param string $url
+     * @return Mollie
+     */
+    public function setMollieApiUrl ($url)
+    {
+        $this->mollieApiUrl = $url;
+
+        return $this;
+    }
+
+    /**
+     * Define Mollie web URL
+     *
+     * @param string $url
+     * @return Mollie
+     */
+    public function setMollieWebUrl ($url)
+    {
+        $this->mollieWebUrl = $url;
+
+        return $this;
+    }
+
 	/**
 	 * Returns the base URL for authorizing a client.
 	 *
@@ -81,7 +117,7 @@ public function __construct(array $options = [], array $collaborators = [])
 	 */
 	public function getBaseAuthorizationUrl ()
 	{
-		return static::MOLLIE_WEB_URL . '/oauth2/authorize';
+		return $this->mollieWebUrl . '/oauth2/authorize';
 	}
 
 	/**
@@ -94,7 +130,7 @@ public function getBaseAuthorizationUrl ()
 	 */
 	public function getBaseAccessTokenUrl (array $params)
 	{
-		return static::MOLLIE_API_URL . '/oauth2/tokens';
+		return $this->mollieApiUrl . '/oauth2/tokens';
 	}
 
 	/**
diff --git a/tests/src/Provider/MollieTest.php b/tests/src/Provider/MollieTest.php
index 5436430..311e2bb 100644
--- a/tests/src/Provider/MollieTest.php
+++ b/tests/src/Provider/MollieTest.php
@@ -1,20 +1,30 @@
 <?php namespace Mollie\OAuth2\Client\Test\Provider;
 
+use GuzzleHttp\ClientInterface;
+use League\OAuth2\Client\Provider\Exception\IdentityProviderException;
+use League\OAuth2\Client\Token\AccessToken;
 use Mockery as m;
 use Mollie\OAuth2\Client\Provider\Mollie;
+use Psr\Http\Message\ResponseInterface;
 
 class MollieTest extends \PHPUnit_Framework_TestCase
 {
+    const MOCK_CLIENT_ID = 'app_mock_client_id';
+    const MOCK_SECRET = 'mock_secret';
+    const REDIRECT_URI = 'none';
+
+    const OPTIONS = [
+        'clientId' => self::MOCK_CLIENT_ID,
+        'clientSecret' => self::MOCK_SECRET,
+        'redirectUri' => self::REDIRECT_URI,
+    ];
+
     protected $provider;
 
-	protected function setUp ()
-	{
-		$this->provider = new Mollie([
-			'clientId'     => 'app_mock_client_id',
-			'clientSecret' => 'mock_secret',
-			'redirectUri'  => 'none',
-		]);
-	}
+    protected function setUp()
+    {
+        $this->provider = new Mollie(self::OPTIONS);
+    }
 
     public function tearDown()
     {
@@ -27,7 +37,7 @@ public function testClientIdShouldThrowExceptionWhenNotPrefixed()
         $this->expectException(\DomainException::class);
         $this->expectExceptionMessage("Mollie needs the client ID to be prefixed with " . Mollie::CLIENT_ID_PREFIX . ".");
 
-        $provider = new \Mollie\OAuth2\Client\Provider\Mollie([
+        new Mollie([
             'clientId'     => 'not_pefixed_client_id',
             'clientSecret' => 'mock_secret',
             'redirectUri'  => 'none',
@@ -37,44 +47,48 @@ public function testClientIdShouldThrowExceptionWhenNotPrefixed()
     public function testGetBaseAccessTokenUrl()
     {
         $params = [];
+
         $url = $this->provider->getBaseAccessTokenUrl($params);
-        $uri = parse_url($url);
-        $this->assertEquals('/oauth2/tokens', $uri['path']);
+
+        $this->assertEquals('https://api.mollie.com/oauth2/tokens', $url);
     }
 
     public function testAuthorizationUrl()
     {
-        $url = $this->provider->getAuthorizationUrl();
-        $uri = parse_url($url);
-        parse_str($uri['query'], $query);
-
-        $this->assertArrayHasKey('client_id', $query);
-        $this->assertArrayHasKey('redirect_uri', $query);
-        $this->assertArrayHasKey('state', $query);
-        $this->assertArrayHasKey('scope', $query);
-        $this->assertArrayHasKey('response_type', $query);
-        $this->assertArrayHasKey('approval_prompt', $query);
-        $this->assertNotNull($this->provider->getState());
+        $authUrl = $this->provider->getAuthorizationUrl();
+
+        list($url, $queryString) = explode('?', $authUrl);
+        parse_str($queryString, $query);
+
+        $this->assertEquals('https://www.mollie.com/oauth2/authorize', $url);
+        $this->assertEquals([
+            'state' => $this->provider->getState(),
+            'client_id' => self::MOCK_CLIENT_ID,
+            'redirect_uri' => self::REDIRECT_URI,
+            'scope' => 'organizations.read',
+            'response_type' => 'code',
+            'approval_prompt' => 'auto',
+        ], $query);
+        $this->assertRegExp('/^[a-f0-9]{32}$/i', $this->provider->getState());
     }
 
     public function testResourceOwnerDetailsUrl()
     {
-        $token = m::mock(\League\OAuth2\Client\Token\AccessToken::class);
+        $token = m::mock(AccessToken::class);
 
         $url = $this->provider->getResourceOwnerDetailsUrl($token);
-        $uri = parse_url($url);
 
-        $this->assertEquals('/v2/organizations/me', $uri['path']);
+        $this->assertEquals('https://api.mollie.com/v2/organizations/me', $url);
     }
 
     public function testGetAccessToken()
     {
-        $response = m::mock(\Psr\Http\Message\ResponseInterface::class);
+        $response = m::mock(ResponseInterface::class);
         $response->shouldReceive('getBody')->andReturn('{"access_token":"mock_access_token", "token_type":"bearer"}');
         $response->shouldReceive('getHeader')->andReturn(['content-type' => 'json']);
         $response->shouldReceive('getStatusCode')->andReturn(200);
 
-        $client = m::mock(\GuzzleHttp\ClientInterface::class);
+        $client = m::mock(ClientInterface::class);
         $client->shouldReceive('send')->times(1)->andReturn($response);
 
         $this->provider->setHttpClient($client);
@@ -87,38 +101,37 @@ public function testGetAccessToken()
         $this->assertNull($token->getResourceOwnerId());
     }
 
-    /**
-     * @expectedException \League\OAuth2\Client\Provider\Exception\IdentityProviderException
-     */
     public function testExceptionThrownWhenErrorObjectReceived()
     {
         $message = uniqid();
         $status = rand(400, 600);
 
-        $postResponse = m::mock(\Psr\Http\Message\ResponseInterface::class);
+        $postResponse = m::mock(ResponseInterface::class);
         $postResponse->shouldReceive('getBody')->andReturn('{"error":{"type":"request","message":"'.$message.'"}}');
         $postResponse->shouldReceive('getHeader')->andReturn(['content-type' => 'json']);
         $postResponse->shouldReceive('getStatusCode')->andReturn($status);
 
-        $client = m::mock(\GuzzleHttp\ClientInterface::class);
+        $client = m::mock(ClientInterface::class);
         $client->shouldReceive('send')
             ->times(1)
             ->andReturn($postResponse);
 
+        $this->expectException(IdentityProviderException::class);
+
         $this->provider->setHttpClient($client);
         $this->provider->getAccessToken('authorization_code', ['code' => 'mock_authorization_code']);
     }
 
     public function testUserData()
     {
-        $postResponse = m::mock(\Psr\Http\Message\ResponseInterface::class);
+        $postResponse = m::mock(ResponseInterface::class);
         $postResponse->shouldReceive('getBody')->andReturn(
             'access_token=mock_access_token&expires=3600&refresh_token=mock_refresh_token'
         );
         $postResponse->shouldReceive('getHeader')->andReturn(['content-type' => 'application/x-www-form-urlencoded']);
         $postResponse->shouldReceive('getStatusCode')->andReturn(200);
 
-        $accountResponse = m::mock(\Psr\Http\Message\ResponseInterface::class);
+        $accountResponse = m::mock(ResponseInterface::class);
         $accountResponse->shouldReceive('getBody')->andReturn(
             '{
                 "resource": "organization",
@@ -175,7 +188,7 @@ public function testUserData()
         $accountResponse->shouldReceive('getHeader')->andReturn(['content-type' => 'json']);
         $accountResponse->shouldReceive('getStatusCode')->andReturn(200);
 
-        $client = m::mock(\GuzzleHttp\ClientInterface::class);
+        $client = m::mock(ClientInterface::class);
         $client->shouldReceive('send')
             ->times(2)
             ->andReturn($postResponse, $accountResponse);
@@ -201,4 +214,19 @@ public function testUserData()
         );
         $this->assertEquals('370355724', $array['registrationNumber']);
     }
-}
\ No newline at end of file
+
+    public function testWhenDefiningADifferentMollieApiUrlThenUseThisOnApiCalls()
+    {
+        $this->provider->setMollieApiUrl('https://api.mollie.nl');
+
+        $this->assertEquals('https://api.mollie.nl/oauth2/tokens', $this->provider->getBaseAccessTokenUrl([]));
+    }
+
+    public function testWhenDefiningADifferentMollieWebUrlThenUseThisForAuthorize()
+    {
+        $this->provider->setMollieWebUrl('https://www.mollie.nl');
+
+        list($url) = explode('?', $this->provider->getAuthorizationUrl());
+        $this->assertEquals('https://www.mollie.nl/oauth2/authorize', $url);
+    }
+}