diff --git a/.gitignore b/.gitignore
index 29263a8..9530cfa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 vendor
 composer.lock
-humbuglog.txt
\ No newline at end of file
+humbuglog.txt
+
+.idea
\ No newline at end of file
diff --git a/composer.json b/composer.json
index 79ca134..5624362 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,8 @@
     "require": {
         "php": ">=7.3",
         "guzzlehttp/psr7": "^2.1",
-        "psr/log": "^1.0 || ^2.0 || ^3.0"
+        "psr/log": "^1.0 || ^2.0 || ^3.0",
+        "ext-curl": "*"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.5",
diff --git a/src/Debugger/Logger.php b/src/Debugger/Logger.php
index 9477d2b..eaac6d6 100644
--- a/src/Debugger/Logger.php
+++ b/src/Debugger/Logger.php
@@ -28,7 +28,7 @@ public function __construct(LoggerInterface $logger)
      * @param Call $call
      * @param CallInfo | null $info
      */
-    public function debugCall(Call $call, CallInfo $info = null)
+    public function debugCall(Call $call, ?CallInfo $info = null)
     {
         $message = $call->hasException()
             ? 'Thrown exception: ' . $call->getException()->getMessage()
diff --git a/src/Handler/CurlMultiRequestHandler.php b/src/Handler/CurlMultiRequestHandler.php
index fae2ba3..ad714d6 100644
--- a/src/Handler/CurlMultiRequestHandler.php
+++ b/src/Handler/CurlMultiRequestHandler.php
@@ -81,7 +81,6 @@ public function sendMany(CallRegistry $callRegistry)
             $this->getLogger()->debugCall($call, $info);
         
             curl_multi_remove_handle($multiHandle, $handle);
-            curl_close($handle);
         }
         curl_multi_close($multiHandle);
     }
diff --git a/src/Handler/CurlRequestHandler.php b/src/Handler/CurlRequestHandler.php
index 4bf09b4..dc7113e 100644
--- a/src/Handler/CurlRequestHandler.php
+++ b/src/Handler/CurlRequestHandler.php
@@ -77,7 +77,6 @@ public function send(Call $call)
         }
     
         $info = CurlCallInfoFactory::createFromInfo(curl_getinfo($curlHandle));
-        curl_close($curlHandle);
 
         $this->getLogger()->debugCall($call, $info);
     }
@@ -110,8 +109,6 @@ public function sendMany(CallRegistry $callRegistry)
             $info = CurlCallInfoFactory::createFromInfo(curl_getinfo($curlHandle));
             $this->getLogger()->debugCall($call, $info);
         }
-
-        curl_close($curlHandle);
     }
     
     /**
diff --git a/src/Operation/CommandOperation.php b/src/Operation/CommandOperation.php
index 78bd39f..064f61b 100644
--- a/src/Operation/CommandOperation.php
+++ b/src/Operation/CommandOperation.php
@@ -48,11 +48,11 @@ public function set($key, $value)
     
     
     /**
-     * @param UrlQuery $urlQuery
+     * @param UrlQuery|null $urlQuery
      * @param array $extra
      * @return string
      */
-    protected function buildUrlQuery(UrlQuery $urlQuery = null, array $extra = [])
+    protected function buildUrlQuery(?UrlQuery $urlQuery = null, array $extra = [])
     {
         $params = [];
         if (null !== $urlQuery) {
diff --git a/src/Operation/SuccessfulOperationResponse.php b/src/Operation/SuccessfulOperationResponse.php
index 2b0028b..58786bd 100644
--- a/src/Operation/SuccessfulOperationResponse.php
+++ b/src/Operation/SuccessfulOperationResponse.php
@@ -33,7 +33,7 @@ class SuccessfulOperationResponse implements OperationResponse
      * @param int $successCode
      * @param RequestInterface $request
      */
-    public function __construct(ResponseInterface $response, $successCode, RequestInterface $request = null)
+    public function __construct(ResponseInterface $response, $successCode, ?RequestInterface $request = null)
     {
         $this->response = $response;
         $this->successCode = (int) $successCode;