diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4ba9339..849914b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php: ['8.1', '8.2']
+        php: ['8.1', '8.2', '8.3', '8.4']
         symfony: ['4.4.*', '5.4.*', '6.1.*', '6.2.*']
 
     steps:
@@ -44,7 +44,7 @@ jobs:
     strategy:
       max-parallel: 10
       matrix:
-        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
+        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
 
     steps:
       - name: Set up PHP
diff --git a/Makefile b/Makefile
index 14c1583..2cd3cd2 100644
--- a/Makefile
+++ b/Makefile
@@ -18,6 +18,12 @@ test-php81:
 test-php82:
 	docker run --rm -v $(DIR):/project -w /project webdevops/php:8.2 make test
 
+test-php83:
+	docker run --rm -v $(DIR):/project -w /project webdevops/php:8.3 make test
+
+test-php84:
+	docker run --rm -v $(DIR):/project -w /project webdevops/php:8.4 make test
+
 test:
 	composer update --prefer-dist --no-interaction ${COMPOSER_PARAMS}
 	composer test
diff --git a/src/BreadcrumbTrail/Trail.php b/src/BreadcrumbTrail/Trail.php
index 9a28223..6c737d4 100644
--- a/src/BreadcrumbTrail/Trail.php
+++ b/src/BreadcrumbTrail/Trail.php
@@ -104,6 +104,10 @@ public function add($breadcrumbOrTitle, $routeName = null, $routeParameters = []
                 }
 
                 foreach ($routeParameters as $key => $parameterValue) {
+                    if ($parameterValue === null) {
+                        continue;
+                    }
+
                     if (is_numeric($key)) {
                         $routeParameters[$parameterValue] = $request->get($parameterValue);
                         unset($routeParameters[$key]);
diff --git a/tests/BreadcrumbTrail/TrailTest.php b/tests/BreadcrumbTrail/TrailTest.php
index 5f24e87..796585c 100644
--- a/tests/BreadcrumbTrail/TrailTest.php
+++ b/tests/BreadcrumbTrail/TrailTest.php
@@ -29,6 +29,31 @@ public function testRenderSimpleValueObjectValueInBreadcrumbTitle()
         $breadcrumb = $iterator->current();
         self::assertEquals($expected, $breadcrumb->title);
     }
+
+    public function testAddWithNullRouteParameter()
+    {
+        $router = $this->createMock(UrlGeneratorInterface::class);
+        $routeName = 'route_name';
+        $router
+            ->expects(self::once())
+            ->method('generate')
+            ->with($routeName, ['id' => null], UrlGeneratorInterface::ABSOLUTE_URL)
+            ->willReturn('https://example.test/page');
+        $requestStack = new RequestStack();
+        $requestStack->push(new Request());
+
+        $trail = new Trail($router, $requestStack);
+        $title = 'Title';
+        $trail->add($title, $routeName, ['id' => null]);
+
+        $iterator = $trail->getIterator();
+        self::assertCount(1, $iterator);
+
+        /** @var Breadcrumb $breadcrumb */
+        $breadcrumb = $iterator->current();
+        self::assertSame($title, $breadcrumb->title);
+        self::assertSame('https://example.test/page', $breadcrumb->url);
+    }
 }
 
 final class User