diff --git a/src/State/Provider/ContentNegotiationProvider.php b/src/State/Provider/ContentNegotiationProvider.php
index 0ffd42607b6..d9f242ce85e 100644
--- a/src/State/Provider/ContentNegotiationProvider.php
+++ b/src/State/Provider/ContentNegotiationProvider.php
@@ -97,6 +97,14 @@ private function flattenMimeTypes(array $formats): array
      */
     private function getInputFormat(HttpOperation $operation, Request $request): ?string
     {
+        if (
+            false === ($input = $operation->getInput())
+            || (\is_array($input) && null === $input['class'])
+            || false === $operation->canDeserialize()
+        ) {
+            return null;
+        }
+
         $contentType = $request->headers->get('CONTENT_TYPE');
         if (null === $contentType || '' === $contentType) {
             return null;
@@ -108,14 +116,14 @@ private function getInputFormat(HttpOperation $operation, Request $request): ?st
             return $format;
         }
 
-        $supportedMimeTypes = [];
-        foreach ($formats as $mimeTypes) {
-            foreach ($mimeTypes as $mimeType) {
-                $supportedMimeTypes[] = $mimeType;
+        if (!$request->isMethodSafe() && 'DELETE' !== $request->getMethod()) {
+            $supportedMimeTypes = [];
+            foreach ($formats as $mimeTypes) {
+                foreach ($mimeTypes as $mimeType) {
+                    $supportedMimeTypes[] = $mimeType;
+                }
             }
-        }
 
-        if (!$request->isMethodSafe() && 'DELETE' !== $request->getMethod()) {
             throw new UnsupportedMediaTypeHttpException(\sprintf('The content-type "%s" is not supported. Supported MIME types are "%s".', $contentType, implode('", "', $supportedMimeTypes)));
         }
 
diff --git a/tests/State/Provider/ContentNegotiationProviderTest.php b/tests/State/Provider/ContentNegotiationProviderTest.php
index e4eb99ba904..dd610bd4b8d 100644
--- a/tests/State/Provider/ContentNegotiationProviderTest.php
+++ b/tests/State/Provider/ContentNegotiationProviderTest.php
@@ -21,6 +21,7 @@
 use Prophecy\Argument;
 use Prophecy\PhpUnit\ProphecyTrait;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Exception\UnsupportedMediaTypeHttpException;
 
 class ContentNegotiationProviderTest extends TestCase
 {
@@ -60,4 +61,63 @@ public function testRequestWithEmptyContentType(): void
 
         $this->assertSame($expectedResult, $result);
     }
+
+    public function testRequestWhenNoInput(): void
+    {
+        $expectedResult = new \stdClass();
+
+        $decorated = $this->prophesize(ProviderInterface::class);
+        $decorated->provide(Argument::cetera())->willReturn($expectedResult);
+
+        $negotiator = new Negotiator();
+        $formats = ['jsonld' => ['application/ld+json']];
+        $errorFormats = ['jsonld' => ['application/ld+json']];
+
+        $provider = new ContentNegotiationProvider($decorated->reveal(), $negotiator, $formats, $errorFormats);
+
+        $request = new Request(
+            server: [
+                'REQUEST_METHOD' => 'POST',
+                'REQUEST_URI' => '/',
+                'CONTENT_TYPE' => 'some-not-supported/content-type',
+            ],
+            content: ''
+        );
+
+        $operation = new Post();
+        $operation = $operation->withDeserialize(false);
+        $context = ['request' => $request];
+
+        $result = $provider->provide($operation, [], $context);
+
+        $this->assertSame($expectedResult, $result);
+    }
+
+    public function testRequestWithInput(): void
+    {
+        $this->expectException(UnsupportedMediaTypeHttpException::class);
+
+        $decorated = $this->prophesize(ProviderInterface::class);
+
+        $negotiator = new Negotiator();
+        $formats = ['jsonld' => ['application/ld+json']];
+        $errorFormats = ['jsonld' => ['application/ld+json']];
+
+        $provider = new ContentNegotiationProvider($decorated->reveal(), $negotiator, $formats, $errorFormats);
+
+        $request = new Request(
+            server: [
+                'REQUEST_METHOD' => 'POST',
+                'REQUEST_URI' => '/',
+                'CONTENT_TYPE' => 'some-not-supported/content-type',
+            ],
+            content: ''
+        );
+
+        $operation = new Post();
+        $operation = $operation->withDeserialize();
+        $context = ['request' => $request];
+
+        $provider->provide($operation, [], $context);
+    }
 }