diff --git a/composer.json b/composer.json
index c938240..70e6b54 100644
--- a/composer.json
+++ b/composer.json
@@ -44,7 +44,7 @@
   "require-dev": {
     "phpunit/phpunit": "^10.5.9",
     "phpstan/phpstan": "^1.10.57",
-    "friendsofphp/php-cs-fixer": "^v3.48.0"
+    "friendsofphp/php-cs-fixer": "^v3.68.3"
   },
   "autoload": {
     "psr-4": {
diff --git a/src/Encryption.php b/src/Encryption.php
index 89fc8e8..03d1093 100644
--- a/src/Encryption.php
+++ b/src/Encryption.php
@@ -267,9 +267,9 @@ private static function getIKM(string $userAuthToken, string $userPublicKey, str
         if (empty($userAuthToken)) {
             return $sharedSecret;
         }
-        if($contentEncoding === "aesgcm") {
+        if ($contentEncoding === "aesgcm") {
             $info = 'Content-Encoding: auth'.chr(0);
-        } elseif($contentEncoding === "aes128gcm") {
+        } elseif ($contentEncoding === "aes128gcm") {
             $info = "WebPush: info".chr(0).$userPublicKey.$localPublicKey;
         } else {
             throw new \ValueError("This content encoding is not supported.");
diff --git a/src/Subscription.php b/src/Subscription.php
index bad3061..571731a 100644
--- a/src/Subscription.php
+++ b/src/Subscription.php
@@ -25,7 +25,7 @@ public function __construct(
         private ?string $authToken = null,
         private ?string $contentEncoding = null
     ) {
-        if($publicKey || $authToken || $contentEncoding) {
+        if ($publicKey || $authToken || $contentEncoding) {
             $supportedContentEncodings = ['aesgcm', 'aes128gcm'];
             if ($contentEncoding && !in_array($contentEncoding, $supportedContentEncodings, true)) {
                 throw new \ErrorException('This content encoding ('.$contentEncoding.') is not supported.');
diff --git a/src/Utils.php b/src/Utils.php
index 887acb0..ecd33ab 100644
--- a/src/Utils.php
+++ b/src/Utils.php
@@ -75,14 +75,14 @@ public static function checkRequirementExtension(): void
             'mbstring' => '[WebPush] mbstring extension is not loaded but is required for sending push notifications with payload or for VAPID authentication. You can fix this in your php.ini.',
             'openssl'  => '[WebPush] openssl extension is not loaded but is required for sending push notifications with payload or for VAPID authentication. You can fix this in your php.ini.',
         ];
-        foreach($requiredExtensions as $extension => $message) {
-            if(!extension_loaded($extension)) {
+        foreach ($requiredExtensions as $extension => $message) {
+            if (!extension_loaded($extension)) {
                 trigger_error($message, E_USER_WARNING);
             }
         }
 
         // Check optional extensions.
-        if(!extension_loaded("bcmath") && !extension_loaded("gmp")) {
+        if (!extension_loaded("bcmath") && !extension_loaded("gmp")) {
             trigger_error("It is highly recommended to install the GMP or BCMath extension to speed up calculations. The fastest available calculator implementation will be automatically selected at runtime.", E_USER_NOTICE);
         }
     }
@@ -95,11 +95,11 @@ public static function checkRequirementKeyCipherHash(): void
             'prime256v1' => '[WebPush] Openssl does not support required curve prime256v1.',
         ];
         $availableCurves = openssl_get_curve_names();
-        if($availableCurves === false) {
+        if ($availableCurves === false) {
             trigger_error('[WebPush] Openssl does not support curves.', E_USER_WARNING);
         } else {
-            foreach($requiredCurves as $curve => $message) {
-                if(!in_array($curve, $availableCurves, true)) {
+            foreach ($requiredCurves as $curve => $message) {
+                if (!in_array($curve, $availableCurves, true)) {
                     trigger_error($message, E_USER_WARNING);
                 }
             }
@@ -110,8 +110,8 @@ public static function checkRequirementKeyCipherHash(): void
             'aes-128-gcm' => '[WebPush] Openssl does not support required cipher aes-128-gcm.',
         ];
         $availableCiphers = openssl_get_cipher_methods();
-        foreach($requiredCiphers as $cipher => $message) {
-            if(!in_array($cipher, $availableCiphers, true)) {
+        foreach ($requiredCiphers as $cipher => $message) {
+            if (!in_array($cipher, $availableCiphers, true)) {
                 trigger_error($message, E_USER_WARNING);
             }
         }
@@ -121,8 +121,8 @@ public static function checkRequirementKeyCipherHash(): void
             'sha256' => '[WebPush] Php does not support required hmac hash sha256.',
         ];
         $availableHash = hash_hmac_algos();
-        foreach($requiredHash as $hash => $message) {
-            if(!in_array($hash, $availableHash, true)) {
+        foreach ($requiredHash as $hash => $message) {
+            if (!in_array($hash, $availableHash, true)) {
                 trigger_error($message, E_USER_WARNING);
             }
         }
diff --git a/src/WebPush.php b/src/WebPush.php
index 5d6aebe..e470b6e 100644
--- a/src/WebPush.php
+++ b/src/WebPush.php
@@ -235,7 +235,8 @@ protected function createRejectedReport($reason): MessageSentReport
     }
 
     /**
-     * @throws \ErrorException|\Random\RandomException
+     * @throws \ErrorException
+     * add back @throws \Random\RandomException when we drop PHP 8.1 support
      */
     protected function prepare(array $notifications): array
     {
@@ -341,10 +342,10 @@ public function setAutomaticPadding(bool|int $automaticPadding): WebPush
             $automaticPadding = 0;
         }
 
-        if($automaticPadding > Encryption::MAX_PAYLOAD_LENGTH) {
+        if ($automaticPadding > Encryption::MAX_PAYLOAD_LENGTH) {
             throw new \ValueError('Automatic padding is too large. Max is '.Encryption::MAX_PAYLOAD_LENGTH.'. Recommended max is '.Encryption::MAX_COMPATIBILITY_PAYLOAD_LENGTH.' for compatibility reasons (see README).');
         }
-        if($automaticPadding < 0) {
+        if ($automaticPadding < 0) {
             throw new \ValueError('Padding length should be positive or zero.');
         }