diff --git a/composer.json b/composer.json
index 62e5f24..9155a3f 100644
--- a/composer.json
+++ b/composer.json
@@ -19,11 +19,10 @@
     }
   ],
   "require": {
-    "php": "^7.4",
-    "symfony/form": "~3.4|~4.0",
-    "symfony/http-foundation": "~3.4|~4.0",
-    "beberlei/assert": "@stable",
-    "doctrine/collections": "^1.4"
+    "php": "^8.0",
+    "symfony/form": "~5.4",
+    "symfony/http-foundation": "~5.4",
+    "beberlei/assert": "^3.3.2"
   },
   "require-dev": {
     "phpunit/phpunit": "@stable"
diff --git a/src/Mathielen/SapOci/Model/OciBasket.php b/src/Mathielen/SapOci/Model/OciBasket.php
index daaf3d5..ef0a63e 100644
--- a/src/Mathielen/SapOci/Model/OciBasket.php
+++ b/src/Mathielen/SapOci/Model/OciBasket.php
@@ -2,19 +2,20 @@
 
 namespace Mathielen\SapOci\Model;
 
-use Doctrine\Common\Collections\ArrayCollection;
-use Doctrine\Common\Collections\Collection;
+use Assert\Assertion;
 
 class OciBasket implements OciBasketInterface
 {
-	private Collection $items;
+	private array $items;
 
-	public function __construct(Collection $items = null)
+	public function __construct(array $items = [])
 	{
-		$this->items = $items ?: new ArrayCollection();
+		Assertion::allIsInstanceOf($items, OciBasketItemInterface::class);
+
+		$this->items = $items;
 	}
 
-	public function getItems(): Collection
+	public function getItems(): iterable
 	{
 		return $this->items;
 	}
diff --git a/src/Mathielen/SapOci/Model/OciBasketInterface.php b/src/Mathielen/SapOci/Model/OciBasketInterface.php
index c02244d..3649146 100644
--- a/src/Mathielen/SapOci/Model/OciBasketInterface.php
+++ b/src/Mathielen/SapOci/Model/OciBasketInterface.php
@@ -2,9 +2,11 @@
 
 namespace Mathielen\SapOci\Model;
 
-use Doctrine\Common\Collections\Collection;
-
 interface OciBasketInterface
 {
-	public function getItems(): Collection;
+
+	/**
+	 * @return OciBasketItemInterface[]
+	 */
+	public function getItems(): iterable;
 }
diff --git a/src/Mathielen/SapOci/OciFormbuilderFactory.php b/src/Mathielen/SapOci/OciFormbuilderFactory.php
index 419282a..bc697f8 100644
--- a/src/Mathielen/SapOci/OciFormbuilderFactory.php
+++ b/src/Mathielen/SapOci/OciFormbuilderFactory.php
@@ -57,7 +57,7 @@ public function factor(OciBasketInterface $basket): FormBuilderInterface
 
 		$formBuilder = $this
 			->formFactory
-			->createNamedBuilder(null, FormType::class, $formData, $this->defaultFormOptions);
+			->createNamedBuilder('default', FormType::class, $formData, $this->defaultFormOptions);
 
 		foreach (\array_keys($formData) as $formFieldName) {
 			$this->addFormField($formBuilder, $formFieldName);
diff --git a/tests/unit/Mathielen/SapOci/Model/OciModelTest.php b/tests/unit/Mathielen/SapOci/Model/OciModelTest.php
index 7d07605..4c8f7e9 100644
--- a/tests/unit/Mathielen/SapOci/Model/OciModelTest.php
+++ b/tests/unit/Mathielen/SapOci/Model/OciModelTest.php
@@ -26,7 +26,7 @@ public function testConstraints($methodName): void
 		$this->assertTrue(true); //all good
 	}
 
-	public function getConstraintedMethodnames()
+	public static function getConstraintedMethodnames(): iterable
 	{
 		$rfl = new \ReflectionClass(Oci50BasketItem::class);