diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index fb68798..2819371 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -20,8 +20,7 @@ jobs:
                   tools: composer:v2
                   coverage: pcov
 
-            - name: Install dependencies
-              run: composer update --prefer-stable --prefer-dist --no-interaction --no-progress
+            - uses: ramsey/composer-install@v1
 
             - name: Execute tests
               run: vendor/bin/phpunit --verbose
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index b18fa1c..73200c7 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -10,10 +10,12 @@ jobs:
         strategy:
             fail-fast: true
             matrix:
-                php: [7.2, 7.3, 7.4, 8.0]
-                stability: [prefer-lowest, prefer-stable]
+                php: [7.2, 7.3, 7.4, 8.0, 8.1]
+                dependencies:
+                    - lowest
+                    - highest
 
-        name: Tests on PHP ${{ matrix.php }} - ${{ matrix.stability }}
+        name: Tests on PHP ${{ matrix.php }} - ${{ matrix.dependencies }}
 
         steps:
             - name: Checkout code
@@ -26,8 +28,9 @@ jobs:
                   tools: composer:v2
                   coverage: none
 
-            - name: Install dependencies
-              run: composer update --${{ matrix.stability }} --prefer-dist --no-interaction --no-progress
+            - uses: "ramsey/composer-install@v1"
+              with:
+                  dependency-versions: "${{ matrix.dependencies }}"
 
             - name: Execute tests
               run: vendor/bin/phpunit --verbose
diff --git a/composer.json b/composer.json
index a84075f..4441509 100644
--- a/composer.json
+++ b/composer.json
@@ -12,14 +12,14 @@
         }
     ],
     "require": {
-        "php": ">=7.2",
+        "php": "^7.2 | ~8.0.0 | ~8.1.0",
         "guzzlehttp/guzzle": "^6.2 || ^7.0",
         "illuminate/notifications": "~5.5 || ~6.0 || ~7.0 || ~8.0",
         "illuminate/support": "~5.5 || ~6.0 || ~7.0 || ~8.0"
     },
     "require-dev": {
         "mockery/mockery": "^1.2.0",
-        "phpunit/phpunit": "^8.5"
+        "phpunit/phpunit": "^8.5.21 | ^9.4.4"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/Pushbullet.php b/src/Pushbullet.php
index b0b2f45..5f2ac09 100644
--- a/src/Pushbullet.php
+++ b/src/Pushbullet.php
@@ -56,7 +56,6 @@ private function getHeaders(): array
      * Send request to Pushbullet API.
      *
      * @param  array  $params
-     *
      * @return \Psr\Http\Message\ResponseInterface
      */
     public function send($params): ResponseInterface
diff --git a/src/PushbulletChannel.php b/src/PushbulletChannel.php
index e077349..d9bfd66 100644
--- a/src/PushbulletChannel.php
+++ b/src/PushbulletChannel.php
@@ -25,8 +25,8 @@ public function __construct(Pushbullet $pushbullet)
     /**
      * Send the given notification.
      *
-     * @param mixed $notifiable
-     * @param \Illuminate\Notifications\Notification $notification
+     * @param  mixed  $notifiable
+     * @param  \Illuminate\Notifications\Notification  $notification
      *
      * @throws \NotificationChannels\Pushbullet\Exceptions\CouldNotSendNotification
      */
@@ -44,8 +44,7 @@ public function send($notifiable, Notification $notification): void
 
     /**
      * @param $notifiable
-     *
-     * @return  \NotificationChannels\Pushbullet\Targets\Targetable|void
+     * @return \NotificationChannels\Pushbullet\Targets\Targetable|void
      */
     private function getTarget($notifiable): ?Targetable
     {
diff --git a/src/PushbulletMessage.php b/src/PushbulletMessage.php
index 4426e15..9db6b26 100644
--- a/src/PushbulletMessage.php
+++ b/src/PushbulletMessage.php
@@ -43,8 +43,7 @@ class PushbulletMessage
     public $url;
 
     /**
-     * @param string $message
-     *
+     * @param  string  $message
      * @return static
      */
     public static function create($message): self
@@ -53,7 +52,7 @@ public static function create($message): self
     }
 
     /**
-     * @param string $message
+     * @param  string  $message
      */
     public function __construct($message)
     {
@@ -62,7 +61,6 @@ public function __construct($message)
 
     /**
      * @param  \NotificationChannels\Pushbullet\Targets\Targetable  $targetable
-     *
      * @return $this
      */
     public function target(Targetable $targetable): self
@@ -100,7 +98,6 @@ public function link(): self
      * Set notification title.
      *
      * @param  string  $title
-     *
      * @return $this
      */
     public function title($title): self
@@ -114,7 +111,6 @@ public function title($title): self
      * Set notification message.
      *
      * @param  string  $message
-     *
      * @return $this
      */
     public function message($message): self
@@ -128,7 +124,6 @@ public function message($message): self
      * Set notification url (if notification is of `link` type).
      *
      * @param  string  $url
-     *
      * @return $this
      */
     public function url($url): self