diff --git a/phpBB/phpbb/di/service_collection.php b/phpBB/phpbb/di/service_collection.php
index 3a18644891..f0b387a5b1 100644
--- a/phpBB/phpbb/di/service_collection.php
+++ b/phpBB/phpbb/di/service_collection.php
@@ -30,6 +30,28 @@ class service_collection extends \ArrayObject
 		$this->container = $container;
 	}
 
+	/**
+	* {@inheritdoc}
+	*/
+	public function getIterator()
+	{
+		return new service_collection_iterator($this->container, $this);
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function offsetGet($index)
+	{
+		if (($task = parent::offsetGet($index)) == null)
+		{
+			$task = $this->container->get($index);
+			$this->offsetSet($index, $task);
+		}
+
+		return $task;
+	}
+
 	/**
 	* Add a service to the collection
 	*
@@ -38,8 +60,61 @@ class service_collection extends \ArrayObject
 	*/
 	public function add($name)
 	{
-		$task = $this->container->get($name);
-
-		$this->offsetSet($name, $task);
+		$this->offsetSet($name, null);
+	}
+}
+
+
+/**
+* Iterator which load the services when they are requested
+*
+* @package phpBB3
+*/
+class service_collection_iterator extends \ArrayIterator
+{
+	protected $container;
+
+	/**
+	* Construct an ArrayIterator for service_collection
+	*
+	* @param ContainerInterface $container Container object
+	* @param array $array The array or object to be iterated on.
+	* @param int $flags Flags to control the behaviour of the ArrayObject object.
+	* @see ArrayObject::setFlags()
+	*/
+	public function __construct(ContainerInterface $container, $array = array() , $flags = 0)
+	{
+		parent::__construct($array, $flags);
+		$this->container = $container;
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function offsetGet($index)
+	{
+		if (($task = parent::offsetGet($index)) == null)
+		{
+			$task = $this->container->get($index);
+			$this->offsetSet($index, $task);
+		}
+
+		return $task;
+	}
+
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function current()
+	{
+		if (($task = parent::current()) == null)
+		{
+			$name = $this->key();
+			$task = $this->container->get($name);
+			$this->offsetSet($name, $task);
+		}
+
+		return $task;
 	}
 }