diff --git a/app/code/community/Mollie/Mpm/Helper/Data.php b/app/code/community/Mollie/Mpm/Helper/Data.php
index 8fe92340..1c8b9506 100644
--- a/app/code/community/Mollie/Mpm/Helper/Data.php
+++ b/app/code/community/Mollie/Mpm/Helper/Data.php
@@ -628,10 +628,11 @@ public function getStatusPending($storeId = null)
 
     /**
      * @param Mage_Sales_Model_Order $order
-     * @param null                   $status
+     * @param null $status
      *
      * @return bool
      * @throws Mage_Core_Exception
+     * @throws Exception
      */
     public function registerCancellation(Mage_Sales_Model_Order $order, $status = null)
     {
@@ -642,7 +643,13 @@ public function registerCancellation(Mage_Sales_Model_Order $order, $status = nu
             }
 
             $this->addTolog('info', $order->getIncrementId() . ' ' . $comment);
-            $order->registerCancellation($comment)->save();
+            $order->cancel();
+
+            if ($status !== null) {
+                $order->addStatusHistoryComment($comment);
+            }
+
+            $order->save();
             return true;
         }
 
diff --git a/app/code/community/Mollie/Mpm/Model/Totals/PaymentFee/Quote.php b/app/code/community/Mollie/Mpm/Model/Totals/PaymentFee/Quote.php
index 345e8fc8..35a388a9 100644
--- a/app/code/community/Mollie/Mpm/Model/Totals/PaymentFee/Quote.php
+++ b/app/code/community/Mollie/Mpm/Model/Totals/PaymentFee/Quote.php
@@ -45,7 +45,7 @@ public function collect(Mage_Sales_Model_Quote_Address $address)
     public function fetch(Mage_Sales_Model_Quote_Address $address)
     {
         $amount = $address->getMollieMpmPaymentFee();
-        if ($amount) {
+        if (floatval($amount)) {
             $address->addTotal(
                 array(
                     'code' => $this->getCode(),
diff --git a/app/code/community/Mollie/Mpm/Test/Helper/DataTest.php b/app/code/community/Mollie/Mpm/Test/Helper/DataTest.php
index 5cd4aa53..943317da 100644
--- a/app/code/community/Mollie/Mpm/Test/Helper/DataTest.php
+++ b/app/code/community/Mollie/Mpm/Test/Helper/DataTest.php
@@ -288,4 +288,34 @@ public function testGetInvoiceMomentPaidStatusThrowsAnExceptionWhenAWrongMomentI
             $this->assertEquals('Invoice moment not supported: shipment', $exception->getMessage());
         }
     }
+
+    public function testRegisterCancellation()
+    {
+        $order = $this->createMock(Mage::getConfig()->getModelClassName('sales/order'));
+        $order->expects($this->once())->method('cancel');
+        $order->expects($this->never())->method('addStatusHistoryComment');
+        $order->method('getId')->willReturn(-999);
+
+        /** @var Mollie_Mpm_Helper_data $instance */
+        $instance = Mage::helper('mpm');
+
+        $instance->registerCancellation($order);
+    }
+
+    public function testRegisterCancellationWithStatus()
+    {
+        $order = $this->createMock(Mage::getConfig()->getModelClassName('sales/order'));
+        $order->expects($this->once())->method('cancel');
+        $order->method('getId')->willReturn(-999);
+
+        /** @var Mollie_Mpm_Helper_data $instance */
+        $instance = Mage::helper('mpm');
+
+        $status = 'my custom status';
+        $order->expects($this->once())->method('addStatusHistoryComment')->with(
+            $instance->__('The order was canceled, reason: payment %s', $status)
+        );
+
+        $instance->registerCancellation($order, $status);
+    }
 }
diff --git a/app/code/community/Mollie/Mpm/etc/config.xml b/app/code/community/Mollie/Mpm/etc/config.xml
index e603c91b..90f26fdc 100644
--- a/app/code/community/Mollie/Mpm/etc/config.xml
+++ b/app/code/community/Mollie/Mpm/etc/config.xml
@@ -33,7 +33,7 @@
 <config>
     <modules>
         <Mollie_Mpm>
-            <version>5.5.3</version>
+            <version>5.5.4</version>
         </Mollie_Mpm>
     </modules>
     <global>