diff --git a/Describer/SwaggerPhpDescriber.php b/Describer/SwaggerPhpDescriber.php
index 62552b4..0bac7ca 100644
--- a/Describer/SwaggerPhpDescriber.php
+++ b/Describer/SwaggerPhpDescriber.php
@@ -168,7 +168,7 @@ final class SwaggerPhpDescriber extends ExternalDocDescriber implements ModelReg
 
     private function normalizePath(string $path): string
     {
-        if (substr($path, -10) === '.{_format}') {
+        if ('.{_format}' === substr($path, -10)) {
             $path = substr($path, 0, -10);
         }
 
diff --git a/ModelDescriber/JMSModelDescriber.php b/ModelDescriber/JMSModelDescriber.php
index 050f5dc..25e58d1 100644
--- a/ModelDescriber/JMSModelDescriber.php
+++ b/ModelDescriber/JMSModelDescriber.php
@@ -39,8 +39,7 @@ class JMSModelDescriber implements ModelDescriberInterface, ModelRegistryAwareIn
         MetadataFactoryInterface $factory,
         PropertyNamingStrategyInterface $namingStrategy,
         SwaggerPropertyAnnotationReader $swaggerPropertyAnnotationReader
-    )
-    {
+    ) {
         $this->factory = $factory;
         $this->namingStrategy = $namingStrategy;
         $this->swaggerPropertyAnnotationReader = $swaggerPropertyAnnotationReader;
@@ -101,8 +100,9 @@ class JMSModelDescriber implements ModelDescriberInterface, ModelRegistryAwareIn
             }
 
             // read property options from Swagger Property annotation if it exists
-            if($item->reflection !== null)
+            if (null !== $item->reflection) {
                 $this->swaggerPropertyAnnotationReader->updateWithSwaggerPropertyAnnotation($item->reflection, $realProp);
+            }
         }
     }
 
diff --git a/ModelDescriber/ObjectModelDescriber.php b/ModelDescriber/ObjectModelDescriber.php
index 6e4ab58..bb6fad4 100644
--- a/ModelDescriber/ObjectModelDescriber.php
+++ b/ModelDescriber/ObjectModelDescriber.php
@@ -29,8 +29,7 @@ class ObjectModelDescriber implements ModelDescriberInterface, ModelRegistryAwar
     public function __construct(
         PropertyInfoExtractorInterface $propertyInfo,
         SwaggerPropertyAnnotationReader $swaggerPropertyAnnotationReader
-    )
-    {
+    ) {
         $this->propertyInfo = $propertyInfo;
         $this->swaggerPropertyAnnotationReader = $swaggerPropertyAnnotationReader;
     }
@@ -69,16 +68,16 @@ class ObjectModelDescriber implements ModelDescriberInterface, ModelRegistryAwar
                 $property = $property->getItems();
             }
 
-            if ($type->getBuiltinType() === Type::BUILTIN_TYPE_STRING) {
+            if (Type::BUILTIN_TYPE_STRING === $type->getBuiltinType()) {
                 $property->setType('string');
-            } elseif ($type->getBuiltinType() === Type::BUILTIN_TYPE_BOOL) {
+            } elseif (Type::BUILTIN_TYPE_BOOL === $type->getBuiltinType()) {
                 $property->setType('boolean');
-            } elseif ($type->getBuiltinType() === Type::BUILTIN_TYPE_INT) {
+            } elseif (Type::BUILTIN_TYPE_INT === $type->getBuiltinType()) {
                 $property->setType('integer');
-            } elseif ($type->getBuiltinType() === Type::BUILTIN_TYPE_FLOAT) {
+            } elseif (Type::BUILTIN_TYPE_FLOAT === $type->getBuiltinType()) {
                 $property->setType('number');
                 $property->setFormat('float');
-            } elseif ($type->getBuiltinType() === Type::BUILTIN_TYPE_OBJECT) {
+            } elseif (Type::BUILTIN_TYPE_OBJECT === $type->getBuiltinType()) {
                 if (in_array($type->getClassName(), ['DateTime', 'DateTimeImmutable'])) {
                     $property->setType('string');
                     $property->setFormat('date-time');
@@ -88,7 +87,7 @@ class ObjectModelDescriber implements ModelDescriberInterface, ModelRegistryAwar
                     );
                 }
             } else {
-                throw new \Exception(sprintf("Unknown type: %s", $type->getBuiltinType()));
+                throw new \Exception(sprintf('Unknown type: %s', $type->getBuiltinType()));
             }
 
             // read property options from Swagger Property annotation if it exists
diff --git a/ModelDescriber/SwaggerPropertyAnnotationReader.php b/ModelDescriber/SwaggerPropertyAnnotationReader.php
index fe98782..7572bc2 100644
--- a/ModelDescriber/SwaggerPropertyAnnotationReader.php
+++ b/ModelDescriber/SwaggerPropertyAnnotationReader.php
@@ -11,10 +11,10 @@
 
 namespace Nelmio\ApiDocBundle\ModelDescriber;
 
-use EXSyst\Component\Swagger\Schema;
-use EXSyst\Component\Swagger\Items;
-use Swagger\Annotations\Property as SwgProperty;
 use Doctrine\Common\Annotations\Reader;
+use EXSyst\Component\Swagger\Items;
+use EXSyst\Component\Swagger\Schema;
+use Swagger\Annotations\Property as SwgProperty;
 
 /**
  * @internal
@@ -36,20 +36,20 @@ class SwaggerPropertyAnnotationReader
     {
         $swgProperty = $this->annotationsReader->getPropertyAnnotation($reflectionProperty, SwgProperty::class);
         if ($swgProperty instanceof SwgProperty) {
-            if ($swgProperty->type !== null) {
+            if (null !== $swgProperty->type) {
                 $property->setType($swgProperty->type);
             }
-            if ($swgProperty->readOnly !== null) {
+            if (null !== $swgProperty->readOnly) {
                 $property->setReadOnly($swgProperty->readOnly);
             }
             if ($property instanceof Schema) {
-                if ($swgProperty->description !== null) {
+                if (null !== $swgProperty->description) {
                     $property->setDescription($swgProperty->description);
                 }
-                if ($swgProperty->title !== null) {
+                if (null !== $swgProperty->title) {
                     $property->setTitle($swgProperty->title);
                 }
-                if ($swgProperty->example !== null) {
+                if (null !== $swgProperty->example) {
                     $property->setExample((string) $swgProperty->example);
                 }
             }
diff --git a/RouteDescriber/RouteDescriberTrait.php b/RouteDescriber/RouteDescriberTrait.php
index 0de075b..a5e827c 100644
--- a/RouteDescriber/RouteDescriberTrait.php
+++ b/RouteDescriber/RouteDescriberTrait.php
@@ -43,7 +43,7 @@ trait RouteDescriberTrait
 
     private function normalizePath(string $path): string
     {
-        if (substr($path, -10) === '.{_format}') {
+        if ('.{_format}' === substr($path, -10)) {
             $path = substr($path, 0, -10);
         }
 
diff --git a/Tests/Functional/Controller/JMSController.php b/Tests/Functional/Controller/JMSController.php
index a4399cc..3aa6dd6 100644
--- a/Tests/Functional/Controller/JMSController.php
+++ b/Tests/Functional/Controller/JMSController.php
@@ -41,6 +41,5 @@ class JMSController
      */
     public function yamlAction()
     {
-
     }
 }
diff --git a/Tests/Functional/Entity/User.php b/Tests/Functional/Entity/User.php
index 6a43252..ab178ab 100644
--- a/Tests/Functional/Entity/User.php
+++ b/Tests/Functional/Entity/User.php
@@ -19,7 +19,7 @@ use Swagger\Annotations as SWG;
 class User
 {
     /**
-     * @var integer
+     * @var int
      *
      * @SWG\Property(description = "User id", required = true, readOnly = true, title = "userid", example=1)
      */
diff --git a/Tests/Functional/Entity/VirtualProperty.php b/Tests/Functional/Entity/VirtualProperty.php
index 7d7540b..3db68a1 100644
--- a/Tests/Functional/Entity/VirtualProperty.php
+++ b/Tests/Functional/Entity/VirtualProperty.php
@@ -1,13 +1,20 @@
 <?php
 
+/*
+ * This file is part of the NelmioApiDocBundle package.
+ *
+ * (c) Nelmio
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
 
 namespace Nelmio\ApiDocBundle\Tests\Functional\Entity;
 
 use JMS\Serializer\Annotation as Serializer;
 
 /**
- * Class VirtualProperty
- * @package Nelmio\ApiDocBundle\Tests\Functional\Entity
+ * Class VirtualProperty.
  *
  * @Serializer\ExclusionPolicy("all")
  * @Serializer\VirtualProperty(
@@ -18,7 +25,6 @@ use JMS\Serializer\Annotation as Serializer;
  */
 class VirtualProperty
 {
-
     /**
      * @var int
      * @Serializer\Type("integer")
@@ -34,6 +40,6 @@ class VirtualProperty
     public function __construct()
     {
         $this->user = new User();
-        $this->user->setEmail("dummy@test.com");
+        $this->user->setEmail('dummy@test.com');
     }
 }
diff --git a/Tests/Functional/Form/DummyType.php b/Tests/Functional/Form/DummyType.php
index eae8edc..7e977a4 100644
--- a/Tests/Functional/Form/DummyType.php
+++ b/Tests/Functional/Form/DummyType.php
@@ -12,8 +12,8 @@
 namespace Nelmio\ApiDocBundle\Tests\Functional\Form;
 
 use Symfony\Component\Form\AbstractType;
-use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
 use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
+use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
 use Symfony\Component\Form\Extension\Core\Type\TextType;
 use Symfony\Component\Form\FormBuilderInterface;
 
diff --git a/Tests/Functional/Form/UserType.php b/Tests/Functional/Form/UserType.php
index 8e7eb79..4b52fd6 100644
--- a/Tests/Functional/Form/UserType.php
+++ b/Tests/Functional/Form/UserType.php
@@ -24,7 +24,7 @@ class UserType extends AbstractType
         $builder
             ->add('dummy', DummyType::class)
             ->add('dummies', CollectionType::class, [
-                'entry_type' => DummyType::class
+                'entry_type' => DummyType::class,
             ]);
     }
 
diff --git a/Tests/Functional/FunctionalTest.php b/Tests/Functional/FunctionalTest.php
index 6732e93..a804604 100644
--- a/Tests/Functional/FunctionalTest.php
+++ b/Tests/Functional/FunctionalTest.php
@@ -159,9 +159,9 @@ class FunctionalTest extends WebTestCase
                     ],
                     'id' => [
                         'type' => 'integer',
-                        'description' => "User id",
+                        'description' => 'User id',
                         'readOnly' => true,
-                        'title' => "userid",
+                        'title' => 'userid',
                         'example' => 1,
                     ],
                     'email' => [
@@ -206,8 +206,8 @@ class FunctionalTest extends WebTestCase
                 'dummies' => [
                     'items' => ['$ref' => '#/definitions/DummyType'],
                     'type' => 'array',
-                    'example' => sprintf('[{%s}]', DummyType::class)
-                ]
+                    'example' => sprintf('[{%s}]', DummyType::class),
+                ],
             ],
             'required' => ['dummy', 'dummies'],
         ], $this->getModel('UserType')->toArray());
@@ -223,8 +223,8 @@ class FunctionalTest extends WebTestCase
                     'enum' => ['male', 'female'],
                 ],
                 'baz' => [
-                    'type' => 'boolean'
-                ]
+                    'type' => 'boolean',
+                ],
             ],
             'required' => ['foo'],
         ], $this->getModel('DummyType')->toArray());
diff --git a/Tests/Functional/JMSFunctionalTest.php b/Tests/Functional/JMSFunctionalTest.php
index fb13a37..922ae53 100644
--- a/Tests/Functional/JMSFunctionalTest.php
+++ b/Tests/Functional/JMSFunctionalTest.php
@@ -20,9 +20,9 @@ class JMSFunctionalTest extends WebTestCase
             'properties' => [
                 'id' => [
                     'type' => 'integer',
-                    'description' => "User id",
+                    'description' => 'User id',
                     'readOnly' => true,
-                    'title' => "userid",
+                    'title' => 'userid',
                     'example' => 1,
                 ],
                 'email' => [
@@ -32,7 +32,7 @@ class JMSFunctionalTest extends WebTestCase
                 'roles' => [
                     'type' => 'array',
                     'description' => 'User roles',
-                    'title' => "roles",
+                    'title' => 'roles',
                     'example' => '["ADMIN","SUPERUSER"]',
                     'items' => ['type' => 'string'],
                 ],
@@ -61,7 +61,7 @@ class JMSFunctionalTest extends WebTestCase
                     'type' => 'integer',
                 ],
                 'email' => [
-                    'type' => 'string'
+                    'type' => 'string',
                 ],
             ],
         ], $this->getModel('VirtualProperty')->toArray());
diff --git a/composer.json b/composer.json
index 5f1631a..a3466bf 100644
--- a/composer.json
+++ b/composer.json
@@ -22,9 +22,6 @@
         "zircote/swagger-php": "^2.0.9"
     },
     "require-dev": {
-        "symfony/yaml": "Temporary: see https://github.com/symfony/symfony/pull/24634/files#r153192689",
-        "symfony/yaml": "^2.8|^3.0|^4.0",
-
         "symfony/templating": "^2.8|^3.0|^4.0",
         "symfony/twig-bundle": "^3.0|^4.0",
         "symfony/asset": "^2.8|^3.0|^4.0",