diff --git a/Render/RenderOpenApi.php b/Render/RenderOpenApi.php
index b561fa6..c9b7594 100644
--- a/Render/RenderOpenApi.php
+++ b/Render/RenderOpenApi.php
@@ -26,10 +26,10 @@ class RenderOpenApi
     /** @var ContainerInterface */
     private $generatorLocator;
 
-    /** @var array<string, OpenApiRenderer> */
+    /** @var array<string, OpenApiRenderer|null> */
     private $openApiRenderers = [];
 
-    public function __construct(ContainerInterface $generatorLocator, OpenApiRenderer ...$openApiRenderers)
+    public function __construct(ContainerInterface $generatorLocator, ?OpenApiRenderer ...$openApiRenderers)
     {
         $this->generatorLocator = $generatorLocator;
         foreach ($openApiRenderers as $openApiRenderer) {
diff --git a/Tests/Render/RenderOpenApiTest.php b/Tests/Render/RenderOpenApiTest.php
index d9b656b..d24e4f7 100644
--- a/Tests/Render/RenderOpenApiTest.php
+++ b/Tests/Render/RenderOpenApiTest.php
@@ -48,6 +48,19 @@ class RenderOpenApiTest extends TestCase
         $this->renderOpenApi();
     }
 
+    public function testNullFormat()
+    {
+        $openApiRenderer = $this->createMock(OpenApiRenderer::class);
+        $openApiRenderer->method('getFormat')->willReturn($this->format);
+        $openApiRenderer->expects($this->once())->method('render');
+
+        $availableOpenApiRenderers = [
+            $openApiRenderer,
+            null,
+        ];
+        $this->renderOpenApi(...$availableOpenApiRenderers);
+    }
+
     private function renderOpenApi(...$openApiRenderer): void
     {
         $spec = $this->createMock(OpenApi::class);