diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 8e50868..989f5f7 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -14,5 +14,5 @@ jobs:
     name: "PHPUnit"
     uses: "doctrine/.github/.github/workflows/continuous-integration.yml@3.0.0"
     with:
-      php-versions: '["7.1", "7.2", "7.3", "7.4", "8.0", "8.1", "8.2"]'
+      php-versions: '["8.1", "8.2"]'
       composer-root-version: "1.4"
diff --git a/composer.json b/composer.json
index fab8172..179145e 100644
--- a/composer.json
+++ b/composer.json
@@ -16,17 +16,17 @@
         }
     ],
     "require": {
-        "php": "^7.1 || ^8.0"
+        "php": "^8.1"
     },
     "require-dev": {
         "ext-phar":                  "*",
         "ext-pdo":                   "*",
-        "doctrine/coding-standard":  "^9 || ^11",
-        "phpbench/phpbench":         "^0.16 || ^1",
-        "phpstan/phpstan":           "^1.4",
-        "phpstan/phpstan-phpunit":   "^1",
-        "phpunit/phpunit":           "^7.5 || ^8.5 || ^9.5",
-        "vimeo/psalm": "^4.30 || ^5.4"
+        "doctrine/coding-standard":  "^11",
+        "phpbench/phpbench":         "^1.2",
+        "phpstan/phpstan":           "^1.9.4",
+        "phpstan/phpstan-phpunit":   "^1.3",
+        "phpunit/phpunit":           "^9.5.27",
+        "vimeo/psalm":               "^5.4"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index d735c3e..76833e8 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -9,35 +9,15 @@
     <!-- Ignore warnings, show progress of the run and show sniff names -->
     <arg value="nps"/>
 
-    <config name="php_version" value="70100"/>
+    <config name="php_version" value="80100"/>
 
     <file>src</file>
     <file>tests</file>
 
     <rule ref="Doctrine">
-        <exclude name="SlevomatCodingStandard.TypeHints.DeclareStrictTypes"/>
-        <exclude name="SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingParameterTypeHint"/>
-        <exclude name="SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingReturnTypeHint"/>
         <exclude name="SlevomatCodingStandard.Exceptions.ReferenceThrowableOnly.ReferencedGeneralException"/>
     </rule>
 
-    <!-- Disable the rules that will require PHP 7.4 -->
-    <rule ref="SlevomatCodingStandard.TypeHints.PropertyTypeHint">
-        <properties>
-            <property name="enableNativeTypeHint" value="false"/>
-        </properties>
-    </rule>
-
-    <rule ref="SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingNativeTypeHint">
-        <exclude-pattern>src/*</exclude-pattern>
-        <exclude-pattern>tests/DoctrineTest/InstantiatorTestAsset/SerializableArrayObjectAsset.php</exclude-pattern>
-        <exclude-pattern>tests/DoctrineTest/InstantiatorTestAsset/SimpleSerializableAsset.php</exclude-pattern>
-    </rule>
-
-    <rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingNativeTypeHint">
-        <exclude-pattern>*/src/*</exclude-pattern>
-    </rule>
-
     <rule ref="SlevomatCodingStandard.Classes.SuperfluousAbstractClassNaming">
         <exclude-pattern>tests/DoctrineTest/InstantiatorTestAsset/AbstractClassAsset.php</exclude-pattern>
     </rule>
@@ -51,13 +31,4 @@
         <exclude-pattern>src/Doctrine/Instantiator/Exception/ExceptionInterface.php</exclude-pattern>
         <exclude-pattern>src/Doctrine/Instantiator/InstantiatorInterface.php</exclude-pattern>
     </rule>
-
-    <rule ref="Generic.WhiteSpace.ScopeIndent.Incorrect">
-        <!-- see https://github.com/squizlabs/PHP_CodeSniffer/issues/3474 -->
-        <exclude-pattern>tests/DoctrineTest/InstantiatorTestAsset/SimpleEnumAsset.php</exclude-pattern>
-    </rule>
-    <rule ref="Generic.WhiteSpace.ScopeIndent.IncorrectExact">
-        <!-- see https://github.com/squizlabs/PHP_CodeSniffer/issues/3474 -->
-        <exclude-pattern>tests/DoctrineTest/InstantiatorTestAsset/SimpleEnumAsset.php</exclude-pattern>
-    </rule>
 </ruleset>
diff --git a/src/Doctrine/Instantiator/Exception/ExceptionInterface.php b/src/Doctrine/Instantiator/Exception/ExceptionInterface.php
index e6a5195..1e59192 100644
--- a/src/Doctrine/Instantiator/Exception/ExceptionInterface.php
+++ b/src/Doctrine/Instantiator/Exception/ExceptionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Instantiator\Exception;
 
 use Throwable;
diff --git a/src/Doctrine/Instantiator/Exception/InvalidArgumentException.php b/src/Doctrine/Instantiator/Exception/InvalidArgumentException.php
index 33de31c..5b91a00 100644
--- a/src/Doctrine/Instantiator/Exception/InvalidArgumentException.php
+++ b/src/Doctrine/Instantiator/Exception/InvalidArgumentException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Instantiator\Exception;
 
 use InvalidArgumentException as BaseInvalidArgumentException;
@@ -36,7 +38,7 @@ public static function fromAbstractClass(ReflectionClass $reflectionClass): self
     {
         return new self(sprintf(
             'The provided class "%s" is abstract, and cannot be instantiated',
-            $reflectionClass->getName()
+            $reflectionClass->getName(),
         ));
     }
 
@@ -44,7 +46,7 @@ public static function fromEnum(string $className): self
     {
         return new self(sprintf(
             'The provided class "%s" is an enum, and cannot be instantiated',
-            $className
+            $className,
         ));
     }
 }
diff --git a/src/Doctrine/Instantiator/Exception/UnexpectedValueException.php b/src/Doctrine/Instantiator/Exception/UnexpectedValueException.php
index 4e55ac5..4f70ded 100644
--- a/src/Doctrine/Instantiator/Exception/UnexpectedValueException.php
+++ b/src/Doctrine/Instantiator/Exception/UnexpectedValueException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Instantiator\Exception;
 
 use Exception;
@@ -20,15 +22,15 @@ class UnexpectedValueException extends BaseUnexpectedValueException implements E
      */
     public static function fromSerializationTriggeredException(
         ReflectionClass $reflectionClass,
-        Exception $exception
+        Exception $exception,
     ): self {
         return new self(
             sprintf(
                 'An exception was raised while trying to instantiate an instance of "%s" via un-serialization',
-                $reflectionClass->getName()
+                $reflectionClass->getName(),
             ),
             0,
-            $exception
+            $exception,
         );
     }
 
@@ -42,7 +44,7 @@ public static function fromUncleanUnSerialization(
         string $errorString,
         int $errorCode,
         string $errorFile,
-        int $errorLine
+        int $errorLine,
     ): self {
         return new self(
             sprintf(
@@ -50,10 +52,10 @@ public static function fromUncleanUnSerialization(
                 . 'in file "%s" at line "%d"',
                 $reflectionClass->getName(),
                 $errorFile,
-                $errorLine
+                $errorLine,
             ),
             0,
-            new Exception($errorString, $errorCode)
+            new Exception($errorString, $errorCode),
         );
     }
 }
diff --git a/src/Doctrine/Instantiator/Instantiator.php b/src/Doctrine/Instantiator/Instantiator.php
index 484ae26..9bbe327 100644
--- a/src/Doctrine/Instantiator/Instantiator.php
+++ b/src/Doctrine/Instantiator/Instantiator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Instantiator;
 
 use ArrayIterator;
@@ -20,8 +22,6 @@
 use function strlen;
 use function unserialize;
 
-use const PHP_VERSION_ID;
-
 final class Instantiator implements InstantiatorInterface
 {
     /**
@@ -29,35 +29,33 @@ final class Instantiator implements InstantiatorInterface
      * the method {@see \Serializable::unserialize()} when dealing with classes implementing
      * the {@see \Serializable} interface.
      */
-    public const SERIALIZATION_FORMAT_USE_UNSERIALIZER   = 'C';
-    public const SERIALIZATION_FORMAT_AVOID_UNSERIALIZER = 'O';
+    private const SERIALIZATION_FORMAT_USE_UNSERIALIZER   = 'C';
+    private const SERIALIZATION_FORMAT_AVOID_UNSERIALIZER = 'O';
 
     /**
      * Used to instantiate specific classes, indexed by class name.
      *
      * @var callable[]
      */
-    private static $cachedInstantiators = [];
+    private static array $cachedInstantiators = [];
 
     /**
      * Array of objects that can directly be cloned, indexed by class name.
      *
      * @var object[]
      */
-    private static $cachedCloneables = [];
+    private static array $cachedCloneables = [];
 
     /**
-     * @param string $className
      * @phpstan-param class-string<T> $className
      *
-     * @return object
      * @phpstan-return T
      *
      * @throws ExceptionInterface
      *
      * @template T of object
      */
-    public function instantiate($className)
+    public function instantiate(string $className): object
     {
         if (isset(self::$cachedCloneables[$className])) {
             /** @phpstan-var T */
@@ -80,12 +78,11 @@ public function instantiate($className)
      *
      * @phpstan-param class-string<T> $className
      *
-     * @return object
      * @phpstan-return T
      *
      * @template T of object
      */
-    private function buildAndCacheFromFactory(string $className)
+    private function buildAndCacheFromFactory(string $className): object
     {
         $factory  = self::$cachedInstantiators[$className] = $this->buildFactory($className);
         $instance = $factory();
@@ -123,14 +120,12 @@ private function buildFactory(string $className): callable
             '%s:%d:"%s":0:{}',
             is_subclass_of($className, Serializable::class) ? self::SERIALIZATION_FORMAT_USE_UNSERIALIZER : self::SERIALIZATION_FORMAT_AVOID_UNSERIALIZER,
             strlen($className),
-            $className
+            $className,
         );
 
         $this->checkIfUnSerializationIsSupported($reflectionClass, $serializedString);
 
-        return static function () use ($serializedString) {
-            return unserialize($serializedString);
-        };
+        return static fn () => unserialize($serializedString);
     }
 
     /**
@@ -149,7 +144,7 @@ private function getReflectionClass(string $className): ReflectionClass
             throw InvalidArgumentException::fromNonExistingClass($className);
         }
 
-        if (PHP_VERSION_ID >= 80100 && enum_exists($className, false)) {
+        if (enum_exists($className, false)) {
             throw InvalidArgumentException::fromEnum($className);
         }
 
@@ -177,7 +172,7 @@ private function checkIfUnSerializationIsSupported(ReflectionClass $reflectionCl
                 $message,
                 $code,
                 $file,
-                $line
+                $line,
             );
 
             return true;
diff --git a/src/Doctrine/Instantiator/InstantiatorInterface.php b/src/Doctrine/Instantiator/InstantiatorInterface.php
index 10508b5..c6ebe35 100644
--- a/src/Doctrine/Instantiator/InstantiatorInterface.php
+++ b/src/Doctrine/Instantiator/InstantiatorInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Instantiator;
 
 use Doctrine\Instantiator\Exception\ExceptionInterface;
@@ -10,15 +12,13 @@
 interface InstantiatorInterface
 {
     /**
-     * @param string $className
      * @phpstan-param class-string<T> $className
      *
-     * @return object
      * @phpstan-return T
      *
      * @throws ExceptionInterface
      *
      * @template T of object
      */
-    public function instantiate($className);
+    public function instantiate(string $className): object;
 }
diff --git a/tests/DoctrineTest/InstantiatorPerformance/InstantiatorPerformanceBench.php b/tests/DoctrineTest/InstantiatorPerformance/InstantiatorPerformanceBench.php
index 1d6857e..295d49d 100644
--- a/tests/DoctrineTest/InstantiatorPerformance/InstantiatorPerformanceBench.php
+++ b/tests/DoctrineTest/InstantiatorPerformance/InstantiatorPerformanceBench.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorPerformance;
 
 use ArrayObject;
@@ -17,8 +19,7 @@
  */
 class InstantiatorPerformanceBench
 {
-    /** @var Instantiator */
-    private $instantiator;
+    private Instantiator $instantiator;
 
     public function init(): void
     {
diff --git a/tests/DoctrineTest/InstantiatorTest/Exception/InvalidArgumentExceptionTest.php b/tests/DoctrineTest/InstantiatorTest/Exception/InvalidArgumentExceptionTest.php
index 5f32d92..6be98d7 100644
--- a/tests/DoctrineTest/InstantiatorTest/Exception/InvalidArgumentExceptionTest.php
+++ b/tests/DoctrineTest/InstantiatorTest/Exception/InvalidArgumentExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTest\Exception;
 
 use Doctrine\Instantiator\Exception\InvalidArgumentException;
@@ -34,7 +36,7 @@ public function testFromNonExistingTypeWithTrait(): void
 
         self::assertSame(
             sprintf('The provided type "%s" is a trait, and cannot be instantiated', SimpleTraitAsset::class),
-            $exception->getMessage()
+            $exception->getMessage(),
         );
     }
 
@@ -45,9 +47,9 @@ public function testFromNonExistingTypeWithInterface(): void
         self::assertSame(
             sprintf(
                 'The provided type "%s" is an interface, and cannot be instantiated',
-                InstantiatorInterface::class
+                InstantiatorInterface::class,
             ),
-            $exception->getMessage()
+            $exception->getMessage(),
         );
     }
 
@@ -59,9 +61,9 @@ public function testFromAbstractClass(): void
         self::assertSame(
             sprintf(
                 'The provided class "%s" is abstract, and cannot be instantiated',
-                AbstractClassAsset::class
+                AbstractClassAsset::class,
             ),
-            $exception->getMessage()
+            $exception->getMessage(),
         );
     }
 }
diff --git a/tests/DoctrineTest/InstantiatorTest/Exception/UnexpectedValueExceptionTest.php b/tests/DoctrineTest/InstantiatorTest/Exception/UnexpectedValueExceptionTest.php
index b64fdd2..9e1fff1 100644
--- a/tests/DoctrineTest/InstantiatorTest/Exception/UnexpectedValueExceptionTest.php
+++ b/tests/DoctrineTest/InstantiatorTest/Exception/UnexpectedValueExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTest\Exception;
 
 use Doctrine\Instantiator\Exception\UnexpectedValueException;
@@ -27,7 +29,7 @@ public function testFromSerializationTriggeredException(): void
         self::assertSame(
             'An exception was raised while trying to instantiate an instance of "'
             . self::class . '" via un-serialization',
-            $exception->getMessage()
+            $exception->getMessage(),
         );
     }
 
@@ -40,9 +42,9 @@ public function testFromUncleanUnSerialization(): void
             sprintf(
                 'Could not produce an instance of "%s" '
                 . 'via un-serialization, since an error was triggered in file "bar" at line "456"',
-                AbstractClassAsset::class
+                AbstractClassAsset::class,
             ),
-            $exception->getMessage()
+            $exception->getMessage(),
         );
 
         $previous = $exception->getPrevious();
diff --git a/tests/DoctrineTest/InstantiatorTest/InstantiatorTest.php b/tests/DoctrineTest/InstantiatorTest/InstantiatorTest.php
index 3e2a2c2..3760e3b 100644
--- a/tests/DoctrineTest/InstantiatorTest/InstantiatorTest.php
+++ b/tests/DoctrineTest/InstantiatorTest/InstantiatorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTest;
 
 use ArrayObject;
@@ -31,8 +33,6 @@
 use function str_replace;
 use function uniqid;
 
-use const PHP_VERSION_ID;
-
 /**
  * Tests for {@see \Doctrine\Instantiator\Instantiator}
  *
@@ -40,8 +40,7 @@
  */
 class InstantiatorTest extends TestCase
 {
-    /** @var Instantiator */
-    private $instantiator;
+    private Instantiator $instantiator;
 
     protected function setUp(): void
     {
@@ -158,11 +157,6 @@ public function getInvalidClassNames(): Generator
         yield 'interface' => [InstantiatorInterface::class];
         yield 'abstract class' => [AbstractClassAsset::class];
         yield 'trait' => [SimpleTraitAsset::class];
-
-        if (PHP_VERSION_ID < 80100) {
-            return;
-        }
-
         yield 'enum' => [SimpleEnumAsset::class];
     }
 }
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/AbstractClassAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/AbstractClassAsset.php
index 4981d75..bf0bb88 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/AbstractClassAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/AbstractClassAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 /**
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/ArrayObjectAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/ArrayObjectAsset.php
index 8e1fb0c..d386033 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/ArrayObjectAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/ArrayObjectAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use ArrayObject;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/ExceptionAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/ExceptionAsset.php
index ef8476f..3408184 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/ExceptionAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/ExceptionAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use BadMethodCallException;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/FinalExceptionAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/FinalExceptionAsset.php
index acaa327..0a24826 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/FinalExceptionAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/FinalExceptionAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use BadMethodCallException;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/PharAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/PharAsset.php
index 4249045..b7094e1 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/PharAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/PharAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use BadMethodCallException;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/PharExceptionAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/PharExceptionAsset.php
index b63505b..87ede4a 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/PharExceptionAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/PharExceptionAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use BadMethodCallException;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/SerializableArrayObjectAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/SerializableArrayObjectAsset.php
index 9b4b771..2ca484c 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/SerializableArrayObjectAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/SerializableArrayObjectAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use ArrayObject;
@@ -37,7 +39,7 @@ public function unserialize($serialized): void
     }
 
     /** @param mixed[] $data */
-    public function __unserialize($data): void
+    public function __unserialize(array $data): void
     {
         throw new BadMethodCallException('Not supposed to be called!');
     }
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/SerializableFinalInternalChildAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/SerializableFinalInternalChildAsset.php
index d4631b3..d18a4b6 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/SerializableFinalInternalChildAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/SerializableFinalInternalChildAsset.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace DoctrineTest\InstantiatorTestAsset;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/SimpleEnumAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/SimpleEnumAsset.php
index 9add64c..f1d2125 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/SimpleEnumAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/SimpleEnumAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 enum SimpleEnumAsset
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/SimpleSerializableAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/SimpleSerializableAsset.php
index 102d306..aa1b649 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/SimpleSerializableAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/SimpleSerializableAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use BadMethodCallException;
@@ -32,7 +34,7 @@ public function serialize(): string
      *
      * @throws BadMethodCallException
      */
-    public function unserialize($serialized): void
+    public function unserialize(string $serialized): void
     {
         throw new BadMethodCallException('Not supposed to be called!');
     }
@@ -44,7 +46,7 @@ public function __serialize(): array
     }
 
     /** @param mixed[] $data */
-    public function __unserialize($data): void
+    public function __unserialize(array $data): void
     {
         throw new BadMethodCallException('Not supposed to be called!');
     }
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/SimpleTraitAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/SimpleTraitAsset.php
index 15f9676..6aba577 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/SimpleTraitAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/SimpleTraitAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 /**
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/UnCloneableAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/UnCloneableAsset.php
index f0f792a..ef0cdc2 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/UnCloneableAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/UnCloneableAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use BadMethodCallException;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/UnserializeExceptionArrayObjectAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/UnserializeExceptionArrayObjectAsset.php
index 9d81534..2a07a3c 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/UnserializeExceptionArrayObjectAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/UnserializeExceptionArrayObjectAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use ArrayObject;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/WakeUpNoticesAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/WakeUpNoticesAsset.php
index 85315a3..1249449 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/WakeUpNoticesAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/WakeUpNoticesAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use ArrayObject;
diff --git a/tests/DoctrineTest/InstantiatorTestAsset/XMLReaderAsset.php b/tests/DoctrineTest/InstantiatorTestAsset/XMLReaderAsset.php
index af53037..62416a8 100644
--- a/tests/DoctrineTest/InstantiatorTestAsset/XMLReaderAsset.php
+++ b/tests/DoctrineTest/InstantiatorTestAsset/XMLReaderAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DoctrineTest\InstantiatorTestAsset;
 
 use BadMethodCallException;