diff --git a/.circleci/config.yml b/.circleci/config.yml
index 195f62ba28b..4e70760d9cb 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -117,7 +117,7 @@ jobs:
           name: Run PHPStan
           command: |-
             export PATH="$PATH:$HOME/.composer/vendor/bin"
-            phpstan analyse -c phpstan.neon -l5 --ansi src tests
+            phpstan analyse -c phpstan.neon -l6 --ansi src tests
 
   phpunit-coverage:
     docker:
diff --git a/phpstan.neon b/phpstan.neon
index cdbf7f29c4d..dc4e45a29a8 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -14,9 +14,12 @@ parameters:
         - '#Access to an undefined property object::\$isIdentifierComposite.#'
         - '#Call to an undefined method Doctrine\\Common\\Persistence\\ObjectManager::getConnection\(\)#'
         - '#Call to an undefined method PHPUnit\\Framework\\MockObject\\MockObject::[a-zA-Z0-9_]+\(\)#'
-        - '#Call to an undefined method Prophecy\\Prophecy\\ObjectProphecy::[a-zA-Z0-9_]+\(\)#'
+        - '#Call to an undefined method Prophecy\\Prophecy\\ObjectProphecy(|.*)?::[a-zA-Z0-9_]+\(\)#'
         - '#Method ApiPlatform\\Core\\Tests\\Bridge\\Doctrine\\Orm\\ItemDataProviderTest::getManagerRegistry\(\) should return Doctrine\\Common\\Persistence\\ManagerRegistry but returns object\.#'
         - '#Method ApiPlatform\\Core\\Tests\\Bridge\\Doctrine\\Orm\\Util\\IdentifierManagerTraitTest::getObjectManager\(\) should return Doctrine\\Common\\Persistence\\ObjectManager but returns object\.#'
+        - '#Parameter \#1 \$function of function call_user_func expects callable, .+ given\.#'
+        - '#Parameter \#1 \$classes of class ApiPlatform\\Core\\Metadata\\Resource\\ResourceNameCollection constructor expects array<string>, array<int, int\|string> given\.#'
+        - '#Method ApiPlatform\\Core\\Util\\RequestParser::parseRequestParams\(\) should return array but returns array\|false\.#'
         # Temporary fix while the PHPStan extension for Prophecy isn't compatible with 0.10
         - '#Parameter .* expects .*, .*object.* given\.#'
         - '#Parameter \#[0-9] \$filterLocator of class ApiPlatform\\Core\\Bridge\\Doctrine\\Orm\\Extension\\FilterExtension constructor expects ApiPlatform\\Core\\Api\\FilterCollection|Psr\\Container\\ContainerInterface(\|null)?, ArrayObject given\.#'
@@ -25,6 +28,7 @@ parameters:
         # https://github.com/doctrine/doctrine2/pull/7298/files
         - '#Strict comparison using === between null and int will always evaluate to false\.#'
         - '#Strict comparison using !== between null and null will always evaluate to false\.#'
+        - '#Method ApiPlatform\\Core\\(Serializer\\Abstract|JsonApi\\Serializer\\)ItemNormalizer::normalizeRelation\(\) should return array\|string but returns array\|bool\|float\|int\|string\.#'
 
         # Expected, due to deprecations
         - '#Method ApiPlatform\\Core\\Bridge\\Doctrine\\Orm\\Extension\\QueryResult(Item|Collection)ExtensionInterface::getResult\(\) invoked with 4 parameters, 1 required\.#'
diff --git a/src/Annotation/ApiFilter.php b/src/Annotation/ApiFilter.php
index a4b24b7a4ed..b50aae034f6 100644
--- a/src/Annotation/ApiFilter.php
+++ b/src/Annotation/ApiFilter.php
@@ -37,7 +37,7 @@ final class ApiFilter
     public $strategy;
 
     /**
-     * @var string
+     * @var string|FilterInterface
      */
     public $filterClass;
 
diff --git a/src/Annotation/AttributesHydratorTrait.php b/src/Annotation/AttributesHydratorTrait.php
index f46021de6a4..2a5870f1d2f 100644
--- a/src/Annotation/AttributesHydratorTrait.php
+++ b/src/Annotation/AttributesHydratorTrait.php
@@ -50,6 +50,7 @@ private function hydrateAttributes(array $values)
         }
 
         foreach ($values as $key => $value) {
+            $key = (string) $key;
             if (!property_exists($this, $key)) {
                 throw new InvalidArgumentException(sprintf('Unknown property "%s" on annotation "%s".', $key, self::class));
             }
diff --git a/src/Bridge/Doctrine/Orm/Filter/DateFilter.php b/src/Bridge/Doctrine/Orm/Filter/DateFilter.php
index ed645075489..f5904be2546 100644
--- a/src/Bridge/Doctrine/Orm/Filter/DateFilter.php
+++ b/src/Bridge/Doctrine/Orm/Filter/DateFilter.php
@@ -94,7 +94,7 @@ protected function filterProperty(string $property, $values, QueryBuilder $query
         }
 
         $nullManagement = $this->properties[$property] ?? null;
-        $type = $this->getDoctrineFieldType($property, $resourceClass);
+        $type = (string) $this->getDoctrineFieldType($property, $resourceClass);
 
         if (self::EXCLUDE_NULL === $nullManagement) {
             $queryBuilder->andWhere($queryBuilder->expr()->isNotNull(sprintf('%s.%s', $alias, $field)));
@@ -160,6 +160,7 @@ protected function filterProperty(string $property, $values, QueryBuilder $query
      */
     protected function addWhere(QueryBuilder $queryBuilder, QueryNameGeneratorInterface $queryNameGenerator, string $alias, string $field, string $operator, string $value, string $nullManagement = null, $type = null)
     {
+        $type = (string) $type;
         try {
             $value = false === strpos($type, '_immutable') ? new \DateTime($value) : new \DateTimeImmutable($value);
         } catch (\Exception $e) {
@@ -206,7 +207,7 @@ protected function addWhere(QueryBuilder $queryBuilder, QueryNameGeneratorInterf
      */
     protected function isDateField(string $property, string $resourceClass): bool
     {
-        return isset(self::DOCTRINE_DATE_TYPES[$this->getDoctrineFieldType($property, $resourceClass)]);
+        return isset(self::DOCTRINE_DATE_TYPES[(string) $this->getDoctrineFieldType($property, $resourceClass)]);
     }
 
     /**
diff --git a/src/Bridge/Doctrine/Orm/Filter/NumericFilter.php b/src/Bridge/Doctrine/Orm/Filter/NumericFilter.php
index 67518cdc4a0..f1e0a8cc982 100644
--- a/src/Bridge/Doctrine/Orm/Filter/NumericFilter.php
+++ b/src/Bridge/Doctrine/Orm/Filter/NumericFilter.php
@@ -63,7 +63,7 @@ public function getDescription(string $resourceClass): array
 
             $description[$property] = [
                 'property' => $property,
-                'type' => $this->getType($this->getDoctrineFieldType($property, $resourceClass)),
+                'type' => $this->getType((string) $this->getDoctrineFieldType($property, $resourceClass)),
                 'required' => false,
             ];
         }
@@ -114,7 +114,7 @@ protected function filterProperty(string $property, $value, QueryBuilder $queryB
             list($alias, $field) = $this->addJoinsForNestedProperty($property, $alias, $queryBuilder, $queryNameGenerator, $resourceClass);
         }
 
-        if (!isset(self::DOCTRINE_NUMERIC_TYPES[$this->getDoctrineFieldType($property, $resourceClass)])) {
+        if (!isset(self::DOCTRINE_NUMERIC_TYPES[(string) $this->getDoctrineFieldType($property, $resourceClass)])) {
             $this->logger->notice('Invalid filter ignored', [
                 'exception' => new InvalidArgumentException(sprintf('The field "%s" of class "%s" is not a doctrine numeric type.', $field, $resourceClass)),
             ]);
@@ -126,7 +126,7 @@ protected function filterProperty(string $property, $value, QueryBuilder $queryB
 
         $queryBuilder
             ->andWhere(sprintf('%s.%s = :%s', $alias, $field, $valueParameter))
-            ->setParameter($valueParameter, $value, $this->getDoctrineFieldType($property, $resourceClass));
+            ->setParameter($valueParameter, $value, (string) $this->getDoctrineFieldType($property, $resourceClass));
     }
 
     /**
@@ -137,6 +137,6 @@ protected function isNumericField(string $property, string $resourceClass): bool
         $propertyParts = $this->splitPropertyParts($property, $resourceClass);
         $metadata = $this->getNestedMetadata($resourceClass, $propertyParts['associations']);
 
-        return isset(self::DOCTRINE_NUMERIC_TYPES[$metadata->getTypeOfField($propertyParts['field'])]);
+        return isset(self::DOCTRINE_NUMERIC_TYPES[(string) $metadata->getTypeOfField($propertyParts['field'])]);
     }
 }
diff --git a/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php b/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php
index 264bd6943eb..d8524110fa7 100644
--- a/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php
+++ b/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php
@@ -98,7 +98,7 @@ public function getDescription(string $resourceClass): array
             }
 
             if ($metadata->hasField($field)) {
-                $typeOfField = $this->getType($metadata->getTypeOfField($field));
+                $typeOfField = $this->getType((string) $metadata->getTypeOfField($field));
                 $strategy = $this->properties[$property] ?? self::STRATEGY_EXACT;
                 $filterParameterNames = [$property];
 
diff --git a/src/Bridge/Doctrine/Orm/ItemDataProvider.php b/src/Bridge/Doctrine/Orm/ItemDataProvider.php
index f1718eece62..0a9d547c27d 100644
--- a/src/Bridge/Doctrine/Orm/ItemDataProvider.php
+++ b/src/Bridge/Doctrine/Orm/ItemDataProvider.php
@@ -69,7 +69,7 @@ public function getItem(string $resourceClass, $id, string $operationName = null
     {
         $manager = $this->managerRegistry->getManagerForClass($resourceClass);
 
-        if (!($context[IdentifierConverterInterface::HAS_IDENTIFIER_CONVERTER] ?? false)) {
+        if (!\is_array($id) && !($context[IdentifierConverterInterface::HAS_IDENTIFIER_CONVERTER] ?? false)) {
             $id = $this->normalizeIdentifiers($id, $manager, $resourceClass);
         }
 
@@ -87,7 +87,7 @@ public function getItem(string $resourceClass, $id, string $operationName = null
         $queryNameGenerator = new QueryNameGenerator();
         $doctrineClassMetadata = $manager->getClassMetadata($resourceClass);
 
-        $this->addWhereForIdentifiers($id, $queryBuilder, $doctrineClassMetadata);
+        $this->addWhereForIdentifiers((array) $id, $queryBuilder, $doctrineClassMetadata);
 
         foreach ($this->itemExtensions as $extension) {
             $extension->applyToItem($queryBuilder, $queryNameGenerator, $resourceClass, $id, $operationName, $context);
diff --git a/src/Bridge/Doctrine/Orm/SubresourceDataProvider.php b/src/Bridge/Doctrine/Orm/SubresourceDataProvider.php
index 2144abef53f..3f242621721 100644
--- a/src/Bridge/Doctrine/Orm/SubresourceDataProvider.php
+++ b/src/Bridge/Doctrine/Orm/SubresourceDataProvider.php
@@ -191,7 +191,7 @@ private function buildQuery(array $identifiers, array $context, QueryNameGenerat
         foreach ($normalizedIdentifiers as $key => $value) {
             $placeholder = $queryNameGenerator->generateParameterName($key);
             $qb->andWhere("$alias.$key = :$placeholder");
-            $topQueryBuilder->setParameter($placeholder, $value, $classMetadata->getTypeOfField($key));
+            $topQueryBuilder->setParameter($placeholder, $value, (string) $classMetadata->getTypeOfField($key));
         }
 
         // Recurse queries
diff --git a/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php b/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php
index cd1118ab90a..a6986870906 100644
--- a/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php
+++ b/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php
@@ -67,11 +67,11 @@ protected function execute(InputInterface $input, OutputInterface $output)
     {
         $documentation = new Documentation($this->resourceNameCollectionFactory->create(), $this->apiTitle, $this->apiDescription, $this->apiVersion, $this->apiFormats);
         $data = $this->documentationNormalizer->normalize($documentation);
-        $content = $input->getOption('yaml') ? Yaml::dump($data, 6, 4, Yaml::DUMP_OBJECT_AS_MAP | Yaml::DUMP_EMPTY_ARRAY_AS_SEQUENCE) : json_encode($data, JSON_PRETTY_PRINT);
-        if (!empty($input->getOption('output'))) {
-            file_put_contents($input->getOption('output'), $content);
+        $content = $input->getOption('yaml') ? Yaml::dump($data, 6, 4, Yaml::DUMP_OBJECT_AS_MAP | Yaml::DUMP_EMPTY_ARRAY_AS_SEQUENCE) : (json_encode($data, JSON_PRETTY_PRINT) ?: '');
+        if (!empty($filename = $input->getOption('output')) && \is_string($filename)) {
+            file_put_contents($filename, $content);
             $output->writeln(
-                sprintf('Data written to %s', $input->getOption('output'))
+                sprintf('Data written to %s', $filename)
             );
         } else {
             $output->writeln($content);
diff --git a/src/Bridge/Symfony/Routing/ApiLoader.php b/src/Bridge/Symfony/Routing/ApiLoader.php
index 11193791c61..6af14127068 100644
--- a/src/Bridge/Symfony/Routing/ApiLoader.php
+++ b/src/Bridge/Symfony/Routing/ApiLoader.php
@@ -57,7 +57,9 @@ final class ApiLoader extends Loader
 
     public function __construct(KernelInterface $kernel, ResourceNameCollectionFactoryInterface $resourceNameCollectionFactory, ResourceMetadataFactoryInterface $resourceMetadataFactory, OperationPathResolverInterface $operationPathResolver, ContainerInterface $container, array $formats, array $resourceClassDirectories = [], SubresourceOperationFactoryInterface $subresourceOperationFactory = null, bool $graphqlEnabled = false, bool $entrypointEnabled = true, bool $docsEnabled = true)
     {
-        $this->fileLoader = new XmlFileLoader(new FileLocator($kernel->locateResource('@ApiPlatformBundle/Resources/config/routing')));
+        /** @var string[]|string $paths */
+        $paths = $kernel->locateResource('@ApiPlatformBundle/Resources/config/routing');
+        $this->fileLoader = new XmlFileLoader(new FileLocator($paths));
         $this->resourceNameCollectionFactory = $resourceNameCollectionFactory;
         $this->resourceMetadataFactory = $resourceMetadataFactory;
         $this->operationPathResolver = $operationPathResolver;
diff --git a/src/Bridge/Symfony/Routing/IriConverter.php b/src/Bridge/Symfony/Routing/IriConverter.php
index 4852ce49045..4f9e36ac8f4 100644
--- a/src/Bridge/Symfony/Routing/IriConverter.php
+++ b/src/Bridge/Symfony/Routing/IriConverter.php
@@ -96,7 +96,7 @@ public function getItemFromIri(string $iri, array $context = [])
         }
 
         if (isset($attributes['subresource_operation_name'])) {
-            if ($item = $this->getSubresourceData($identifiers, $attributes, $context)) {
+            if (($item = $this->getSubresourceData($identifiers, $attributes, $context)) && !\is_array($item)) {
                 return $item;
             }
 
diff --git a/src/DataProvider/OperationDataProviderTrait.php b/src/DataProvider/OperationDataProviderTrait.php
index e5456ce06e3..d5a656fbfaf 100644
--- a/src/DataProvider/OperationDataProviderTrait.php
+++ b/src/DataProvider/OperationDataProviderTrait.php
@@ -67,7 +67,7 @@ private function getItemData($identifiers, array $attributes, array $context)
      *
      * @throws RuntimeException
      *
-     * @return object|null
+     * @return array|object|null
      */
     private function getSubresourceData($identifiers, array $attributes, array $context)
     {
diff --git a/src/EventListener/AddFormatListener.php b/src/EventListener/AddFormatListener.php
index 3e0974402d0..47d9a6a1354 100644
--- a/src/EventListener/AddFormatListener.php
+++ b/src/EventListener/AddFormatListener.php
@@ -84,6 +84,7 @@ public function onKernelRequest(GetResponseEvent $event)
         }
 
         // First, try to guess the format from the Accept header
+        /** @var string|null $accept */
         $accept = $request->headers->get('Accept');
         if (null !== $accept) {
             if (null === $acceptHeader = $this->negotiator->getBest($accept, $mimeTypes)) {
diff --git a/src/Filter/QueryParameterValidateListener.php b/src/Filter/QueryParameterValidateListener.php
index 488d55ddf30..ffb919a69fd 100644
--- a/src/Filter/QueryParameterValidateListener.php
+++ b/src/Filter/QueryParameterValidateListener.php
@@ -86,7 +86,7 @@ private function isRequiredFilterValid(string $name, Request $request): bool
             return false;
         }
 
-        $rootName = array_keys($matches)[0] ?? '';
+        $rootName = (string) (array_keys($matches)[0] ?? null);
         if (!$rootName) {
             return false;
         }
diff --git a/src/GraphQl/Action/EntrypointAction.php b/src/GraphQl/Action/EntrypointAction.php
index 3cf3e78abe5..e92ddac8bf6 100644
--- a/src/GraphQl/Action/EntrypointAction.php
+++ b/src/GraphQl/Action/EntrypointAction.php
@@ -83,7 +83,7 @@ private function parseRequest(Request $request): array
         }
 
         if ('json' === $request->getContentType()) {
-            $input = \json_decode($request->getContent(), true);
+            $input = \json_decode((string) $request->getContent(), true);
 
             if (isset($input['query'])) {
                 $query = $input['query'];
diff --git a/src/GraphQl/Serializer/ItemNormalizer.php b/src/GraphQl/Serializer/ItemNormalizer.php
index 13124284977..8702210928c 100644
--- a/src/GraphQl/Serializer/ItemNormalizer.php
+++ b/src/GraphQl/Serializer/ItemNormalizer.php
@@ -79,7 +79,7 @@ protected function getAllowedAttributes($classOrObject, array $context, $attribu
 
         if (($context['api_denormalize'] ?? false) && false !== ($indexId = array_search('id', $allowedAttributes, true))) {
             $allowedAttributes[] = '_id';
-            array_splice($allowedAttributes, $indexId, 1);
+            array_splice($allowedAttributes, (int) $indexId, 1);
         }
 
         return $allowedAttributes;
diff --git a/src/GraphQl/Type/SchemaBuilder.php b/src/GraphQl/Type/SchemaBuilder.php
index 63de7b4c9ba..d142bd9378a 100644
--- a/src/GraphQl/Type/SchemaBuilder.php
+++ b/src/GraphQl/Type/SchemaBuilder.php
@@ -288,7 +288,7 @@ private function mergeFilterArgs(array $args, array $parsed, ResourceMetadata $r
             if (\is_array($value)) {
                 $value = $this->mergeFilterArgs($args[$key] ?? [], $value);
                 if (!isset($value['#name'])) {
-                    $name = (false === $pos = strrpos($original, '[')) ? $original : substr($original, 0, $pos);
+                    $name = (false === $pos = strrpos($original, '[')) ? $original : substr($original, 0, (int) $pos);
                     $value['#name'] = ($resourceMetadata ? $resourceMetadata->getShortName() : '').'Filter_'.strtr($name, ['[' => '_', ']' => '', '.' => '__']);
                 }
             }
diff --git a/src/Metadata/Extractor/XmlExtractor.php b/src/Metadata/Extractor/XmlExtractor.php
index 4f64b95acff..a3e041e0d8d 100644
--- a/src/Metadata/Extractor/XmlExtractor.php
+++ b/src/Metadata/Extractor/XmlExtractor.php
@@ -33,6 +33,7 @@ final class XmlExtractor extends AbstractExtractor
     protected function extractPath(string $path)
     {
         try {
+            /** @var \SimpleXMLElement $xml */
             $xml = simplexml_import_dom(XmlUtils::loadFile($path, self::RESOURCE_SCHEMA));
         } catch (\InvalidArgumentException $e) {
             throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
diff --git a/src/Metadata/Extractor/YamlExtractor.php b/src/Metadata/Extractor/YamlExtractor.php
index c76fbc5450e..f965bf34244 100644
--- a/src/Metadata/Extractor/YamlExtractor.php
+++ b/src/Metadata/Extractor/YamlExtractor.php
@@ -32,7 +32,7 @@ final class YamlExtractor extends AbstractExtractor
     protected function extractPath(string $path)
     {
         try {
-            $resourcesYaml = Yaml::parse(file_get_contents($path), Yaml::PARSE_CONSTANT);
+            $resourcesYaml = Yaml::parse((string) file_get_contents($path), Yaml::PARSE_CONSTANT);
         } catch (ParseException $e) {
             $e->setParsedFile($path);
 
diff --git a/src/Metadata/Resource/Factory/OperationResourceMetadataFactory.php b/src/Metadata/Resource/Factory/OperationResourceMetadataFactory.php
index 50145a37c5b..f11556bc09a 100644
--- a/src/Metadata/Resource/Factory/OperationResourceMetadataFactory.php
+++ b/src/Metadata/Resource/Factory/OperationResourceMetadataFactory.php
@@ -112,7 +112,7 @@ private function normalize(bool $collection, ResourceMetadata $resourceMetadata,
                 $operation = [];
             }
 
-            $upperOperationName = strtoupper($operationName);
+            $upperOperationName = strtoupper((string) $operationName);
             if ($collection) {
                 $supported = isset(self::SUPPORTED_COLLECTION_OPERATION_METHODS[$upperOperationName]);
             } else {
diff --git a/src/Operation/Factory/SubresourceOperationFactory.php b/src/Operation/Factory/SubresourceOperationFactory.php
index 412d36e7bed..d930ad8eae0 100644
--- a/src/Operation/Factory/SubresourceOperationFactory.php
+++ b/src/Operation/Factory/SubresourceOperationFactory.php
@@ -157,10 +157,10 @@ private function computeSubresourceOperations(string $resourceClass, array &$tre
                 if (isset($subresourceOperation['path'])) {
                     $operation['path'] = $subresourceOperation['path'];
                 } else {
-                    $operation['path'] = str_replace(self::FORMAT_SUFFIX, '', $parentOperation['path']);
+                    $operation['path'] = str_replace(self::FORMAT_SUFFIX, '', (string) $parentOperation['path']);
 
                     if ($parentOperation['collection']) {
-                        list($key) = end($operation['identifiers']);
+                        [$key] = end($operation['identifiers']);
                         $operation['path'] .= sprintf('/{%s}', $key);
                     }
 
diff --git a/src/Swagger/Serializer/ApiGatewayNormalizer.php b/src/Swagger/Serializer/ApiGatewayNormalizer.php
index f9937f0a5e1..babd97f6097 100644
--- a/src/Swagger/Serializer/ApiGatewayNormalizer.php
+++ b/src/Swagger/Serializer/ApiGatewayNormalizer.php
@@ -93,8 +93,8 @@ public function normalize($object, $format = null, array $context = [])
 
         // $data['definitions'] is an instance of \ArrayObject
         foreach (array_keys($data['definitions']->getArrayCopy()) as $definition) {
-            if (!preg_match('/^[A-z]+$/', $definition)) {
-                $data['definitions'][str_replace(['-', '_'], '', $definition)] = $data['definitions'][$definition];
+            if (!preg_match('/^[A-z]+$/', (string) $definition)) {
+                $data['definitions'][str_replace(['-', '_'], '', (string) $definition)] = $data['definitions'][$definition];
                 unset($data['definitions'][$definition]);
             }
         }
diff --git a/src/Util/RequestParser.php b/src/Util/RequestParser.php
index 4adb2a47c19..2247e8e2c39 100644
--- a/src/Util/RequestParser.php
+++ b/src/Util/RequestParser.php
@@ -35,7 +35,7 @@ private function __construct()
     public static function parseAndDuplicateRequest(Request $request): Request
     {
         $query = self::parseRequestParams(self::getQueryString($request) ?? '');
-        $body = self::parseRequestParams($request->getContent());
+        $body = self::parseRequestParams((string) $request->getContent());
 
         return $request->duplicate($query, $body);
     }
diff --git a/tests/Bridge/Symfony/Bundle/Command/SwaggerCommandTest.php b/tests/Bridge/Symfony/Bundle/Command/SwaggerCommandTest.php
index eb532c2ada5..2e2769b7181 100644
--- a/tests/Bridge/Symfony/Bundle/Command/SwaggerCommandTest.php
+++ b/tests/Bridge/Symfony/Bundle/Command/SwaggerCommandTest.php
@@ -67,11 +67,12 @@ public function testExecuteWithYaml()
 
     public function testWriteToFile()
     {
+        /** @var string $tmpFile */
         $tmpFile = tempnam(sys_get_temp_dir(), 'test_write_to_file');
 
         $this->tester->run(['command' => 'api:swagger:export', '--output' => $tmpFile]);
 
-        $this->assertJson(file_get_contents($tmpFile));
+        $this->assertJson((string) @file_get_contents($tmpFile));
         @unlink($tmpFile);
     }
 
diff --git a/tests/GraphQl/Type/SchemaBuilderTest.php b/tests/GraphQl/Type/SchemaBuilderTest.php
index b725b7db84d..baf97ad07b6 100644
--- a/tests/GraphQl/Type/SchemaBuilderTest.php
+++ b/tests/GraphQl/Type/SchemaBuilderTest.php
@@ -183,6 +183,7 @@ public function testGetSchema(bool $paginationEnabled)
             $this->assertEquals(GraphQLType::nonNull(GraphQLType::int()), $objectPropertyFieldType->getField('totalCount')->getType());
             /** @var ListOfType $edgesType */
             $edgesType = $objectPropertyFieldType->getFields()['edges']->getType();
+            /** @var ObjectType $edgeType */
             $edgeType = $edgesType->getWrappedType();
             $this->assertSame('ShortName1Edge', $edgeType->name);
             $this->assertEquals(GraphQLType::nonNull(GraphQLType::string()), $edgeType->getField('cursor')->getType());
diff --git a/tests/Swagger/Serializer/ApiGatewayNormalizerTest.php b/tests/Swagger/Serializer/ApiGatewayNormalizerTest.php
index b6ef51b7f8e..d8f76b83e26 100644
--- a/tests/Swagger/Serializer/ApiGatewayNormalizerTest.php
+++ b/tests/Swagger/Serializer/ApiGatewayNormalizerTest.php
@@ -30,7 +30,7 @@ final class ApiGatewayNormalizerTest extends TestCase
     private $documentationNormalizerMock;
 
     /**
-     * @var ObjectProphecy|\stdClass
+     * @var ObjectProphecy
      */
     private $objectMock;