diff --git a/src/OpenClassrooms/UseCase/Application/Services/Event/EventFactory.php b/src/OpenClassrooms/UseCase/Application/Services/Event/EventFactory.php
index 28408df..5c32506 100644
--- a/src/OpenClassrooms/UseCase/Application/Services/Event/EventFactory.php
+++ b/src/OpenClassrooms/UseCase/Application/Services/Event/EventFactory.php
@@ -17,8 +17,8 @@ interface EventFactory
      */
     public function make(
         $eventName,
-        UseCaseRequest $useCaseRequest = null,
-        UseCaseResponse $useCaseResponse = null,
-        \Exception $exception = null
+        ?UseCaseRequest $useCaseRequest = null,
+        ?UseCaseResponse $useCaseResponse = null,
+        ?\Exception $exception = null
     );
 }
diff --git a/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Cache/CacheProxyStrategy.php b/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Cache/CacheProxyStrategy.php
index e1c6a0d..8f844c4 100644
--- a/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Cache/CacheProxyStrategy.php
+++ b/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Cache/CacheProxyStrategy.php
@@ -67,7 +67,7 @@ public function postExecute(ProxyStrategyRequest $proxyStrategyRequest)
         return new ProxyStrategyResponseDTO($item->get(), false);
     }
 
-    private function fetchWithNamespace(string $id, string $namespace = null): CacheItemInterface
+    private function fetchWithNamespace(string $id, ?string $namespace = null): CacheItemInterface
     {
         if ($namespace !== null) {
             $namespaceId = $this->cache->getItem($namespace);
@@ -78,7 +78,7 @@ private function fetchWithNamespace(string $id, string $namespace = null): Cache
         return $this->cache->getItem($id);
     }
 
-    private function saveWithNamespace(string $id, mixed $data, string $namespace = null, int $lifetime = null): CacheItemInterface
+    private function saveWithNamespace(string $id, mixed $data, ?string $namespace = null, ?int $lifetime = null): CacheItemInterface
     {
         if ($namespace !== null) {
             $namespaceId = $this->cache->getItem($namespace);
diff --git a/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Event/DTO/EventProxyStrategyRequestBuilderImpl.php b/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Event/DTO/EventProxyStrategyRequestBuilderImpl.php
index 40472cf..10fd394 100644
--- a/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Event/DTO/EventProxyStrategyRequestBuilderImpl.php
+++ b/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/Event/DTO/EventProxyStrategyRequestBuilderImpl.php
@@ -52,7 +52,7 @@ public function withUseCaseRequest(UseCaseRequest $useCaseRequest)
     /**
      * @return EventProxyStrategyRequestBuilder
      */
-    public function withUseCaseResponse(UseCaseResponse $useCaseResponse = null)
+    public function withUseCaseResponse(?UseCaseResponse $useCaseResponse = null)
     {
         $this->request->useCaseResponse = $useCaseResponse;
 
diff --git a/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/ProxyStrategyRequestFactoryImpl.php b/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/ProxyStrategyRequestFactoryImpl.php
index 7c13dd7..82c65f6 100644
--- a/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/ProxyStrategyRequestFactoryImpl.php
+++ b/src/OpenClassrooms/UseCase/Application/Services/Proxy/Strategies/Impl/ProxyStrategyRequestFactoryImpl.php
@@ -175,7 +175,7 @@ public function createPostExecuteRequest(
         $annotation,
         UseCase $useCase,
         UseCaseRequest $useCaseRequest,
-        UseCaseResponse $useCaseResponse = null
+        ?UseCaseResponse $useCaseResponse = null
     ) {
         $request = new ProxyStrategyRequestDTO();
         switch ($annotation) {
diff --git a/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxy.php b/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxy.php
index 061a674..a401bf8 100644
--- a/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxy.php
+++ b/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxy.php
@@ -179,7 +179,7 @@ private function sortPreStrategies()
         usort(
             $this->strategies,
             function (ProxyStrategyBag $s1, ProxyStrategyBag $s2) {
-                return array_search($s1->getType(), UseCaseProxy::$strategyPreOrder) >
+                return array_search($s1->getType(), UseCaseProxy::$strategyPreOrder) <=>
                 array_search($s2->getType(), UseCaseProxy::$strategyPreOrder);
             }
         );
@@ -215,7 +215,7 @@ private function sortPostStrategies()
         usort(
             $this->strategies,
             function (ProxyStrategyBag $s1, ProxyStrategyBag $s2) {
-                return array_search($s1->getType(), UseCaseProxy::$strategyPostOrder) >
+                return array_search($s1->getType(), UseCaseProxy::$strategyPostOrder) <=>
                 array_search($s2->getType(), UseCaseProxy::$strategyPostOrder);
             }
         );
@@ -242,7 +242,7 @@ private function sortOnExceptionStrategies()
         usort(
             $this->strategies,
             function (ProxyStrategyBag $s1, ProxyStrategyBag $s2) {
-                return array_search($s1->getType(), UseCaseProxy::$strategyOnExceptionOrder) >
+                return array_search($s1->getType(), UseCaseProxy::$strategyOnExceptionOrder) <=>
                 array_search($s2->getType(), UseCaseProxy::$strategyOnExceptionOrder);
             }
         );
diff --git a/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxyBuilder.php b/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxyBuilder.php
index b58c02b..1bdc7b6 100644
--- a/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxyBuilder.php
+++ b/src/OpenClassrooms/UseCase/Application/Services/Proxy/UseCases/UseCaseProxyBuilder.php
@@ -85,7 +85,7 @@ abstract public function create(UseCase $useCase);
     /**
      * @return UseCaseProxyBuilder
      */
-    public function withCache(CacheItemPoolInterface $cache = null)
+    public function withCache(?CacheItemPoolInterface $cache = null)
     {
         $this->cache = $cache;
 
@@ -95,7 +95,7 @@ public function withCache(CacheItemPoolInterface $cache = null)
     /**
      * @return UseCaseProxyBuilder
      */
-    public function withEventSender(EventSender $event = null)
+    public function withEventSender(?EventSender $event = null)
     {
         $this->event = $event;
 
@@ -105,7 +105,7 @@ public function withEventSender(EventSender $event = null)
     /**
      * @return UseCaseProxyBuilder
      */
-    public function withEventFactory(EventFactory $eventFactory = null)
+    public function withEventFactory(?EventFactory $eventFactory = null)
     {
         $this->eventFactory = $eventFactory;
 
@@ -132,7 +132,7 @@ public function withReader(Reader $reader)
     /**
      * @return UseCaseProxyBuilder
      */
-    public function withSecurity(Security $security = null)
+    public function withSecurity(?Security $security = null)
     {
         $this->security = $security;
 
@@ -142,7 +142,7 @@ public function withSecurity(Security $security = null)
     /**
      * @return UseCaseProxyBuilder
      */
-    public function withTransaction(Transaction $transaction = null)
+    public function withTransaction(?Transaction $transaction = null)
     {
         $this->transaction = $transaction;
 
diff --git a/tests/OpenClassrooms/UseCase/Application/Services/Event/EventFactorySpy.php b/tests/OpenClassrooms/UseCase/Application/Services/Event/EventFactorySpy.php
index 726171b..cf32be5 100644
--- a/tests/OpenClassrooms/UseCase/Application/Services/Event/EventFactorySpy.php
+++ b/tests/OpenClassrooms/UseCase/Application/Services/Event/EventFactorySpy.php
@@ -36,9 +36,9 @@ class EventFactorySpy implements EventFactory
      */
     public function make(
         $eventName,
-        UseCaseRequest $useCaseRequest = null,
-        UseCaseResponse $useCaseResponse = null,
-        \Exception $exception = null
+        ?UseCaseRequest $useCaseRequest = null,
+        ?UseCaseResponse $useCaseResponse = null,
+        ?\Exception $exception = null
     ) {
         $this->useCaseRequest = $useCaseRequest;
         $this->useCaseResponse = $useCaseResponse;
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index ff94591..97b0d28 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -4,7 +4,7 @@
 
 use Composer\Autoload\ClassLoader;
 
-error_reporting(E_ALL | E_STRICT);
+error_reporting(E_ALL);
 
 /** @var ClassLoader $loader */
 require __DIR__.'/../vendor/autoload.php';