diff --git a/src/AbstractDatatransGateway.php b/src/AbstractDatatransGateway.php
index cc3bd36..a026034 100644
--- a/src/AbstractDatatransGateway.php
+++ b/src/AbstractDatatransGateway.php
@@ -41,7 +41,7 @@ public function getDefaultParameters()
                 self::RETURN_METHOD_POST,
                 self::RETURN_METHOD_GET,
             ],
-            'errorUrl'      => '',
+            'errorUrl'      => null,
             'language'     => [
                 null, // account default
                 'de', // German
diff --git a/src/Message/AbstractRedirectRequest.php b/src/Message/AbstractRedirectRequest.php
index 7eb6ae4..db1ece5 100644
--- a/src/Message/AbstractRedirectRequest.php
+++ b/src/Message/AbstractRedirectRequest.php
@@ -218,7 +218,11 @@ public function getData()
         // These URLs are optional here, if set in the account.
 
         if ($this->getReturnUrl() !== null) {
+            // Default the errorUrl to the same returnURL.
+            // It can be overridden later if required.
+
             $data['successUrl'] = $this->getReturnUrl();
+            $data['errorUrl'] = $this->getReturnUrl();
         }
 
         if ($this->getCancelUrl() !== null) {
diff --git a/src/Message/TokenizeRequest.php b/src/Message/TokenizeRequest.php
index 3d03325..85bce3b 100644
--- a/src/Message/TokenizeRequest.php
+++ b/src/Message/TokenizeRequest.php
@@ -31,7 +31,7 @@ class TokenizeRequest extends AbstractRedirectRequest
      */
     public function getData()
     {
-        $this->validate('merchantId', 'transactionId', 'sign', 'returnUrl', 'errorUrl', 'cancelUrl');
+        $this->validate('merchantId', 'transactionId', 'sign', 'returnUrl', 'cancelUrl');
 
         $data = array(
             'merchantId' => $this->getMerchantId(),
@@ -44,7 +44,7 @@ public function getData()
 
         $data['successUrl'] = $this->getReturnUrl();
         $data['cancelUrl'] = $this->getCancelUrl();
-        $data['errorUrl'] = $this->getErrorUrl();
+        $data['errorUrl'] = $this->getErrorUrl() ?: $this->getReturnUrl();
         $data['cancelUrl'] = $this->getCancelUrl();
 
         return $data;
diff --git a/tests/Message/PurchaseRequestTest.php b/tests/Message/PurchaseRequestTest.php
index 483eb8a..b4762f1 100644
--- a/tests/Message/PurchaseRequestTest.php
+++ b/tests/Message/PurchaseRequestTest.php
@@ -47,4 +47,35 @@ public function testGetDataWithoutCard()
 
         $this->assertEquals($expected, $this->request->getData());
     }
+
+    /**
+     * No errorUrl set explicitly.
+     */
+    public function testErrorUrlDefaults()
+    {
+        $this->request->initialize(array(
+            'merchantId' => 'asdf',
+            'sign' => '123',
+            'testMode' => true,
+            'amount' => '12.00',
+            'currency' => 'CHF',
+            'transactionId' => '123',
+            'returnUrl' => 'https://www.example.com/return',
+            'cancelUrl' => 'https://www.example.com/cancel'
+        ));
+
+        $expected = array(
+            'merchantId' => 'asdf',
+            'refno' => '123',
+            'amount' => 1200,
+            'currency' => 'CHF',
+            'sign' => '123',
+            'reqtype' => 'CAA',
+            'successUrl' => 'https://www.example.com/return',
+            'errorUrl' => 'https://www.example.com/return',
+            'cancelUrl' => 'https://www.example.com/cancel'
+        );
+
+        $this->assertEquals($expected, $this->request->getData());
+    }
 }
diff --git a/tests/Message/TokenizeRequestTest.php b/tests/Message/TokenizeRequestTest.php
new file mode 100644
index 0000000..7dfc00e
--- /dev/null
+++ b/tests/Message/TokenizeRequestTest.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace Omnipay\Datatrans\Message;
+
+use Omnipay\Common\CreditCard;
+use Omnipay\Tests\TestCase;
+
+class TokenizeRequestTest extends TestCase
+{
+    /**
+     * @var PurchaseRequest
+     */
+    private $request;
+
+    public function setUp()
+    {
+        parent::setUp();
+
+        $this->request = new TokenizeRequest($this->getHttpClient(), $this->getHttpRequest());
+    }
+
+    public function testGetDataWithoutCard()
+    {
+        $this->request->initialize(array(
+            'merchantId' => 'asdf',
+            'sign' => '123',
+            'testMode' => true,
+            'currency' => 'CHF',
+            'transactionId' => '123',
+            'returnUrl' => 'https://www.example.com/success',
+            'errorUrl' => 'https://www.example.com/error',
+            'cancelUrl' => 'https://www.example.com/cancel'
+        ));
+
+        $expected = array(
+            'merchantId' => 'asdf',
+            'refno' => '123',
+            'amount' => 0,
+            'currency' => 'CHF',
+            'sign' => '123',
+            'successUrl' => 'https://www.example.com/success',
+            'errorUrl' => 'https://www.example.com/error',
+            'cancelUrl' => 'https://www.example.com/cancel',
+            'useAlias' => 'yes',
+        );
+
+        $this->assertEquals($expected, $this->request->getData());
+    }
+
+    /**
+     * No errorUrl set explicitly.
+     */
+    public function testErrorUrlDefaults()
+    {
+        $this->request->initialize(array(
+            'merchantId' => 'asdfxxx',
+            'sign' => '123',
+            'testMode' => true,
+            'currency' => 'CHF',
+            'transactionId' => '123',
+            'returnUrl' => 'https://www.example.com/return',
+            'cancelUrl' => 'https://www.example.com/cancel'
+        ));
+
+        $expected = array(
+            'merchantId' => 'asdfxxx',
+            'refno' => '123',
+            'amount' => 0,
+            'currency' => 'CHF',
+            'sign' => '123',
+            'successUrl' => 'https://www.example.com/return',
+            'errorUrl' => 'https://www.example.com/return',
+            'cancelUrl' => 'https://www.example.com/cancel',
+            'useAlias' => 'yes',
+        );
+
+        $this->assertEquals($expected, $this->request->getData());
+    }
+}