diff --git a/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessage.php b/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessage.php
index 46e996395a..867a39bdac 100644
--- a/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessage.php
+++ b/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessage.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\commerce_checkout\Plugin\Commerce\CheckoutPane;
 
+use Drupal\commerce_checkout\Plugin\Commerce\CheckoutFlow\CheckoutFlowInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Form\FormStateInterface;
 
 /**
@@ -23,7 +25,7 @@ class CompletionMessage extends CheckoutPaneBase {
   /**
    * {@inheritdoc}
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, \Drupal\commerce_checkout\Plugin\Commerce\CheckoutFlow\CheckoutFlowInterface $checkout_flow, \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, CheckoutFlowInterface $checkout_flow, EntityTypeManagerInterface $entity_type_manager) {
     parent::__construct($configuration, $plugin_id, $plugin_definition, $checkout_flow, $entity_type_manager);
     $this->completionMessags = new CompletionMessages();
   }
diff --git a/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessages.php b/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessages.php
index e5a9c91998..51af9655a4 100644
--- a/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessages.php
+++ b/modules/checkout/src/Plugin/Commerce/CheckoutPane/CompletionMessages.php
@@ -3,7 +3,6 @@
 namespace Drupal\commerce_checkout\Plugin\Commerce\CheckoutPane;
 
 use Drupal\Core\StringTranslation\TranslatableMarkup;
-use Drupal\Core\TypedData\TranslatableInterface;
 
 /**
  * Acts as a container to collect all completion messages.
@@ -13,7 +12,7 @@
 class CompletionMessages implements \Iterator, \Countable {
 
   /**
-   * @var \Drupal\Core\TypedData\TranslatableInterface[]
+   * @var \Drupal\Core\StringTranslation\TranslatableMarkup[]
    */
   private $messages;
 
@@ -30,81 +29,58 @@ public function __construct() {
   }
 
   /**
-   * Return the current element
+   * Adds a message to the array.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslatableMarkup $message
+   *   The message to add.
+   */
+  public function addMessage(TranslatableMarkup $message) {
+    $this->messages[] = $message;
+  }
+
+  /**
+   * Gets the current message.
    *
-   * @link http://php.net/manual/en/iterator.current.php
-   * @return mixed Can return any type.
-   * @since 5.0.0
+   * @return \Drupal\Core\StringTranslation\TranslatableMarkup
+   *   The current message.
    */
   public function current() {
     return $this->messages[$this->position];
   }
 
   /**
-   * Move forward to next element
-   *
-   * @link http://php.net/manual/en/iterator.next.php
-   * @return void Any returned value is ignored.
-   * @since 5.0.0
+   * {@inheritdoc}
    */
   public function next() {
     ++$this->position;
   }
 
   /**
-   * Return the key of the current element
-   *
-   * @link http://php.net/manual/en/iterator.key.php
-   * @return mixed scalar on success, or null on failure.
-   * @since 5.0.0
+   * {@inheritdoc}
    */
   public function key() {
     return $this->position;
   }
 
   /**
-   * Checks if current position is valid
-   *
-   * @link http://php.net/manual/en/iterator.valid.php
-   * @return boolean The return value will be casted to boolean and then
-   *   evaluated. Returns true on success or false on failure.
-   * @since 5.0.0
+   * {@inheritdoc}
    */
   public function valid() {
     return isset($this->messages[$this->position]);
   }
 
   /**
-   * Rewind the Iterator to the first element
-   *
-   * @link http://php.net/manual/en/iterator.rewind.php
-   * @return void Any returned value is ignored.
-   * @since 5.0.0
+   * {@inheritdoc}
    */
   public function rewind() {
     $this->position = 0;
   }
 
   /**
-   * Adds a message to the array.
-   *
-   * @param \Drupal\Core\StringTranslation\TranslatableMarkup $message
-   */
-  public function addMessage(TranslatableMarkup $message) {
-    $this->messages[] = $message;
-  }
-
-  /**
-   * Count elements of an object
-   *
-   * @link http://php.net/manual/en/countable.count.php
-   * @return int The custom count as an integer.
-   * </p>
-   * <p>
-   * The return value is cast to an integer.
-   * @since 5.1.0
+   * {@inheritdoc}
    */
   public function count() {
     return count($this->messages);
   }
-}
\ No newline at end of file
+
+}
diff --git a/modules/checkout/templates/commerce-checkout-completion-message.html.twig b/modules/checkout/templates/commerce-checkout-completion-message.html.twig
index 5e6bfc8b6d..2b6fb3e9c0 100644
--- a/modules/checkout/templates/commerce-checkout-completion-message.html.twig
+++ b/modules/checkout/templates/commerce-checkout-completion-message.html.twig
@@ -12,7 +12,7 @@
 #}
 <div class="checkout-complete">
   {% for message in completion_messages %}
-    {{ message }}
+    {{ message }} <br/>
   {% endfor %}
 
   {{ 'Your order number is @number.'|t({'@number': order_entity.getOrderNumber}) }} <br>
diff --git a/modules/checkout/tests/src/Kernel/CompletionMessagesTest.php b/modules/checkout/tests/src/Kernel/CompletionMessagesTest.php
index ba42f4704b..6ad9f65221 100644
--- a/modules/checkout/tests/src/Kernel/CompletionMessagesTest.php
+++ b/modules/checkout/tests/src/Kernel/CompletionMessagesTest.php
@@ -1,10 +1,4 @@
 <?php
-/**
- * Created by PhpStorm.
- * User: robharings
- * Date: 09/09/2017
- * Time: 13:31
- */
 
 namespace Drupal\Tests\commerce_checkout\Kernel;
 
@@ -15,19 +9,27 @@
  * Tests the completion messages class.
  *
  * @covers \Drupal\commerce_checkout\Plugin\Commerce\CheckoutPane\CompletionMessages
+ *
+ * @group commerce
  */
 class CompletionMessagesTest extends CommerceKernelTestBase {
 
   /**
-   * @var CompletionMessages
+   * @var \Drupal\commerce_checkout\Plugin\Commerce\CheckoutPane\CompletionMessages
    */
   private $completionMessages;
 
+  /**
+   * {@inheritdoc}
+   */
   public function setUp() {
     parent::setUp();
     $this->completionMessages = new CompletionMessages();
   }
 
+  /**
+   * Tests add message method.
+   */
   public function testAddMessage() {
     $this->completionMessages->addMessage(t('Message 1'));
     $this->completionMessages->addMessage(t('Message 2'));
@@ -35,6 +37,9 @@ public function testAddMessage() {
     $this->assertCount(2, $this->completionMessages);
   }
 
+  /**
+   * Tests the messages iterator.
+   */
   public function testMessagesIterator() {
     $this->completionMessages->addMessage(t('Message 1'));
     $this->completionMessages->addMessage(t('Message 2'));
@@ -44,4 +49,4 @@ public function testMessagesIterator() {
     $this->assertEquals('Message 2', $this->completionMessages->current()->render());
   }
 
-}
\ No newline at end of file
+}