diff --git a/.github/workflows/buildcheck.yml b/.github/workflows/buildcheck.yml
index 6ba28d5..8ae9a02 100644
--- a/.github/workflows/buildcheck.yml
+++ b/.github/workflows/buildcheck.yml
@@ -16,6 +16,8 @@ jobs:
           - "8.0"
           - "8.1"
           - "8.2"
+          - "8.3"
+          - "8.4"
         composer:
           - ""
           - "--prefer-lowest"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a9bf3d..23ea8d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,14 @@ Changelog
 
 --------
 
+## 2.2.6 - 2024-12-18
+
+### Changed
+
+* [Support] Added support for PHP 8.3 and 8.4.
+
+--------
+
 ## 2.2.5 - 2024-12-18
 
 ### Changed
diff --git a/composer.json b/composer.json
index 032d653..adba155 100644
--- a/composer.json
+++ b/composer.json
@@ -35,7 +35,7 @@
         "phpstan/phpstan-mockery": "^0.12.14",
         "phpstan/phpstan-phpunit": "^0.12.22",
         "squizlabs/php_codesniffer": "^3.6",
-        "phpunit/phpunit": "^9.5"
+        "phpunit/phpunit": "^9.6"
     },
     "autoload": {
         "psr-4": {"duncan3dc\\Sonos\\": "src/"}
diff --git a/src/Alarm.php b/src/Alarm.php
index cd5bdfe..01414b5 100644
--- a/src/Alarm.php
+++ b/src/Alarm.php
@@ -269,11 +269,11 @@ public function setFrequency(int $frequency): AlarmInterface
      * Check or set whether this alarm is active on a particular day.
      *
      * @param int $day Which day to check/set
-     * @param bool $set Set this alarm to be active or not on the specified day
+     * @param ?bool $set Set this alarm to be active or not on the specified day
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    protected function onHandler(int $day, bool $set = null)
+    protected function onHandler(int $day, ?bool $set = null)
     {
         $frequency = $this->getFrequency();
         if ($set === null) {
@@ -293,11 +293,11 @@ protected function onHandler(int $day, bool $set = null)
     /**
      * Check or set whether this alarm is active on mondays.
      *
-     * @param bool $set Set this alarm to be active or not on mondays
+     * @param ?bool $set Set this alarm to be active or not on mondays
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function onMonday(bool $set = null)
+    public function onMonday(?bool $set = null)
     {
         return $this->onHandler(AlarmInterface::MONDAY, $set);
     }
@@ -306,11 +306,11 @@ public function onMonday(bool $set = null)
     /**
      * Check or set whether this alarm is active on tuesdays.
      *
-     * @param bool $set Set this alarm to be active or not on tuesdays
+     * @param ?bool $set Set this alarm to be active or not on tuesdays
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function onTuesday(bool $set = null)
+    public function onTuesday(?bool $set = null)
     {
         return $this->onHandler(AlarmInterface::TUESDAY, $set);
     }
@@ -319,11 +319,11 @@ public function onTuesday(bool $set = null)
     /**
      * Check or set whether this alarm is active on wednesdays.
      *
-     * @param bool $set Set this alarm to be active or not on wednesdays
+     * @param ?bool $set Set this alarm to be active or not on wednesdays
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function onWednesday(bool $set = null)
+    public function onWednesday(?bool $set = null)
     {
         return $this->onHandler(AlarmInterface::WEDNESDAY, $set);
     }
@@ -332,11 +332,11 @@ public function onWednesday(bool $set = null)
     /**
      * Check or set whether this alarm is active on thursdays.
      *
-     * @param bool $set Set this alarm to be active or not on thursdays
+     * @param ?bool $set Set this alarm to be active or not on thursdays
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function onThursday(bool $set = null)
+    public function onThursday(?bool $set = null)
     {
         return $this->onHandler(AlarmInterface::THURSDAY, $set);
     }
@@ -345,11 +345,11 @@ public function onThursday(bool $set = null)
     /**
      * Check or set whether this alarm is active on fridays.
      *
-     * @param bool $set Set this alarm to be active or not on fridays
+     * @param ?bool $set Set this alarm to be active or not on fridays
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function onFriday(bool $set = null)
+    public function onFriday(?bool $set = null)
     {
         return $this->onHandler(AlarmInterface::FRIDAY, $set);
     }
@@ -358,11 +358,11 @@ public function onFriday(bool $set = null)
     /**
      * Check or set whether this alarm is active on saturdays.
      *
-     * @param bool $set Set this alarm to be active or not on saturdays
+     * @param ?bool $set Set this alarm to be active or not on saturdays
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function onSaturday(bool $set = null)
+    public function onSaturday(?bool $set = null)
     {
         return $this->onHandler(AlarmInterface::SATURDAY, $set);
     }
@@ -371,11 +371,11 @@ public function onSaturday(bool $set = null)
     /**
      * Check or set whether this alarm is active on sundays.
      *
-     * @param bool $set Set this alarm to be active or not on sundays
+     * @param ?bool $set Set this alarm to be active or not on sundays
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function onSunday(bool $set = null)
+    public function onSunday(?bool $set = null)
     {
         return $this->onHandler(AlarmInterface::SUNDAY, $set);
     }
@@ -384,11 +384,11 @@ public function onSunday(bool $set = null)
     /**
      * Check or set whether this alarm is a one time only alarm.
      *
-     * @param bool $set Set this alarm to be a one time only alarm
+     * @param ?bool $set Set this alarm to be a one time only alarm
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function once(bool $set = null)
+    public function once(?bool $set = null)
     {
         if ($set) {
             return $this->setFrequency(AlarmInterface::ONCE);
@@ -400,11 +400,11 @@ public function once(bool $set = null)
     /**
      * Check or set whether this alarm runs every day or not.
      *
-     * @param bool $set Set this alarm to be active every day
+     * @param ?bool $set Set this alarm to be active every day
      *
      * @return bool|AlarmInterface Returns true/false when checking, or AlarmInterface when setting
      */
-    public function daily(bool $set = null)
+    public function daily(?bool $set = null)
     {
         if ($set) {
             return $this->setFrequency(AlarmInterface::DAILY);
diff --git a/src/Controller.php b/src/Controller.php
index 76201f1..fdf1d61 100644
--- a/src/Controller.php
+++ b/src/Controller.php
@@ -317,11 +317,11 @@ public function useStream(Stream $stream): ControllerInterface
      *
      * If no speaker is passed then the current controller's is used.
      *
-     * @param SpeakerInterface|null $speaker The speaker to get the line-in from
+     * @param ?SpeakerInterface $speaker The speaker to get the line-in from
      *
      * @return static
      */
-    public function useLineIn(SpeakerInterface $speaker = null): ControllerInterface
+    public function useLineIn(?SpeakerInterface $speaker = null): ControllerInterface
     {
         if ($speaker === null) {
             $speaker = $this;
@@ -649,11 +649,11 @@ public function restoreState(ControllerStateInterface $state): ControllerInterfa
      * This is useful for making announcements over the Sonos network.
      *
      * @param UriInterface $track The track to play
-     * @param int $volume The volume to play the track at
+     * @param ?int $volume The volume to play the track at
      *
      * @return $this
      */
-    public function interrupt(UriInterface $track, int $volume = null): ControllerInterface
+    public function interrupt(UriInterface $track, ?int $volume = null): ControllerInterface
     {
         /**
          * Ensure the track has been generated.
diff --git a/src/Devices/Collection.php b/src/Devices/Collection.php
index c2bdaec..c38ef0f 100644
--- a/src/Devices/Collection.php
+++ b/src/Devices/Collection.php
@@ -31,9 +31,9 @@ final class Collection implements CollectionInterface
     /**
      * Create a new instance.
      *
-     * @param FactoryInterface $factory The factory to create new devices from
+     * @param ?FactoryInterface $factory The factory to create new devices from
      */
-    public function __construct(FactoryInterface $factory = null)
+    public function __construct(?FactoryInterface $factory = null)
     {
         if ($factory === null) {
             $factory = new Factory();
diff --git a/src/Devices/Device.php b/src/Devices/Device.php
index 6229e26..322717c 100644
--- a/src/Devices/Device.php
+++ b/src/Devices/Device.php
@@ -41,10 +41,10 @@ final class Device implements DeviceInterface
      * Create an instance of the Device class.
      *
      * @param string $ip The ip address that the device is listening on
-     * @param CacheInterface $cache The cache object to use for finding Sonos devices on the network
-     * @param LoggerInterface $logger A logging object
+     * @param ?CacheInterface $cache The cache object to use for finding Sonos devices on the network
+     * @param ?LoggerInterface $logger A logging object
      */
-    public function __construct(string $ip, CacheInterface $cache = null, LoggerInterface $logger = null)
+    public function __construct(string $ip, ?CacheInterface $cache = null, ?LoggerInterface $logger = null)
     {
         $this->ip = $ip;
 
diff --git a/src/Devices/Discovery.php b/src/Devices/Discovery.php
index e36119d..490a08f 100644
--- a/src/Devices/Discovery.php
+++ b/src/Devices/Discovery.php
@@ -37,9 +37,9 @@ final class Discovery implements CollectionInterface
     /**
      * Create a new instance.
      *
-     * @param CollectionInterface $collection The device collection to actually use
+     * @param ?CollectionInterface $collection The device collection to actually use
      */
-    public function __construct(CollectionInterface $collection = null)
+    public function __construct(?CollectionInterface $collection = null)
     {
         if ($collection === null) {
             $collection = new Collection();
diff --git a/src/Devices/Factory.php b/src/Devices/Factory.php
index ed1b80a..c592c3a 100644
--- a/src/Devices/Factory.php
+++ b/src/Devices/Factory.php
@@ -22,10 +22,10 @@ final class Factory implements FactoryInterface
     /**
      * Create a new instance.
      *
-     * @param CacheInterface $cache The cache object to use for finding Sonos devices on the network
-     * @param LoggerInterface $logger A logging object
+     * @param ?CacheInterface $cache The cache object to use for finding Sonos devices on the network
+     * @param ?LoggerInterface $logger A logging object
      */
-    public function __construct(CacheInterface $cache = null, LoggerInterface $logger = null)
+    public function __construct(?CacheInterface $cache = null, ?LoggerInterface $logger = null)
     {
         if ($cache === null) {
             $cache = new ArrayPool();
diff --git a/src/Helper.php b/src/Helper.php
index 00d1f5b..735aad8 100644
--- a/src/Helper.php
+++ b/src/Helper.php
@@ -68,7 +68,7 @@ public static function setMode(array $options): string
      * @param string $id The ID of the track
      * @param string $parent The ID of the parent
      * @param array<string, mixed> $extra An xml array of extra attributes for this item
-     * @param string $service The Sonos service ID to use
+     * @param ?string $service The Sonos service ID to use
      *
      * @return string
      */
@@ -76,7 +76,7 @@ public static function createMetaDataXml(
         string $id,
         string $parent = "-1",
         array $extra = [],
-        string $service = null
+        ?string $service = null
     ): string {
         if ($service !== null) {
             $extra["desc"] = [
diff --git a/src/Interfaces/AlarmInterface.php b/src/Interfaces/AlarmInterface.php
index 9ea39b9..3ddb9db 100644
--- a/src/Interfaces/AlarmInterface.php
+++ b/src/Interfaces/AlarmInterface.php
@@ -126,91 +126,91 @@ public function setFrequency(int $frequency): AlarmInterface;
     /**
      * Check or set whether this alarm is active on mondays.
      *
-     * @param bool $set Set this alarm to be active or not on mondays
+     * @param ?bool $set Set this alarm to be active or not on mondays
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function onMonday(bool $set = null);
+    public function onMonday(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm is active on tuesdays.
      *
-     * @param bool $set Set this alarm to be active or not on tuesdays
+     * @param ?bool $set Set this alarm to be active or not on tuesdays
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function onTuesday(bool $set = null);
+    public function onTuesday(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm is active on wednesdays.
      *
-     * @param bool $set Set this alarm to be active or not on wednesdays
+     * @param ?bool $set Set this alarm to be active or not on wednesdays
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function onWednesday(bool $set = null);
+    public function onWednesday(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm is active on thursdays.
      *
-     * @param bool $set Set this alarm to be active or not on thursdays
+     * @param ?bool $set Set this alarm to be active or not on thursdays
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function onThursday(bool $set = null);
+    public function onThursday(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm is active on fridays.
      *
-     * @param bool $set Set this alarm to be active or not on fridays
+     * @param ?bool $set Set this alarm to be active or not on fridays
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function onFriday(bool $set = null);
+    public function onFriday(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm is active on saturdays.
      *
-     * @param bool $set Set this alarm to be active or not on saturdays
+     * @param ?bool $set Set this alarm to be active or not on saturdays
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function onSaturday(bool $set = null);
+    public function onSaturday(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm is active on sundays.
      *
-     * @param bool $set Set this alarm to be active or not on sundays
+     * @param ?bool $set Set this alarm to be active or not on sundays
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function onSunday(bool $set = null);
+    public function onSunday(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm is a one time only alarm.
      *
-     * @param bool $set Set this alarm to be a one time only alarm
+     * @param ?bool $set Set this alarm to be a one time only alarm
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function once(bool $set = null);
+    public function once(?bool $set = null);
 
 
     /**
      * Check or set whether this alarm runs every day or not.
      *
-     * @param bool $set Set this alarm to be active every day
+     * @param ?bool $set Set this alarm to be active every day
      *
      * @return bool|static Returns true/false when checking, or static when setting
      */
-    public function daily(bool $set = null);
+    public function daily(?bool $set = null);
 
 
     /**
diff --git a/src/Interfaces/ControllerInterface.php b/src/Interfaces/ControllerInterface.php
index 107aff9..2d201bd 100644
--- a/src/Interfaces/ControllerInterface.php
+++ b/src/Interfaces/ControllerInterface.php
@@ -162,11 +162,11 @@ public function useStream(Stream $stream): ControllerInterface;
      *
      * If no speaker is passed then the current controller's is used.
      *
-     * @param SpeakerInterface|null $speaker The speaker to get the line-in from
+     * @param ?SpeakerInterface $speaker The speaker to get the line-in from
      *
      * @return self
      */
-    public function useLineIn(SpeakerInterface $speaker = null): ControllerInterface;
+    public function useLineIn(?SpeakerInterface $speaker = null): ControllerInterface;
 
 
     /**
@@ -322,9 +322,9 @@ public function restoreState(ControllerStateInterface $state): ControllerInterfa
      * This is useful for making announcements over the Sonos network.
      *
      * @param UriInterface $track The track to play
-     * @param int $volume The volume to play the track at
+     * @param ?int $volume The volume to play the track at
      *
      * @return self
      */
-    public function interrupt(UriInterface $track, int $volume = null): ControllerInterface;
+    public function interrupt(UriInterface $track, ?int $volume = null): ControllerInterface;
 }
diff --git a/src/Interfaces/QueueInterface.php b/src/Interfaces/QueueInterface.php
index a81c95e..2d68128 100644
--- a/src/Interfaces/QueueInterface.php
+++ b/src/Interfaces/QueueInterface.php
@@ -25,12 +25,12 @@ public function getTracks(int $start = 0, int $total = 0): array;
      * Add a track to the queue.
      *
      * @param string|UriInterface $track The URI of the track to add, or an object that implements the UriInterface
-     * @param int $position The position to insert the track in the queue (zero-based),
+     * @param ?int $position The position to insert the track in the queue (zero-based),
      *                      by default the track will be added to the end of the queue
      *
      * @return QueueInterface
      */
-    public function addTrack($track, int $position = null): QueueInterface;
+    public function addTrack($track, ?int $position = null): QueueInterface;
 
 
     /**
@@ -38,12 +38,12 @@ public function addTrack($track, int $position = null): QueueInterface;
      *
      * @param string[]|UriInterface[] $tracks An array where each element is either the URI of the tracks to add,
      *                                          or an object that implements the UriInterface
-     * @param int $position The position to insert the tracks in the queue (zero-based),
+     * @param ?int $position The position to insert the tracks in the queue (zero-based),
      *                      by default the tracks will be added to the end of the queue
      *
      * @return QueueInterface
      */
-    public function addTracks(array $tracks, int $position = null): QueueInterface;
+    public function addTracks(array $tracks, ?int $position = null): QueueInterface;
 
 
     /**
diff --git a/src/Network.php b/src/Network.php
index fd07b27..014833f 100644
--- a/src/Network.php
+++ b/src/Network.php
@@ -49,9 +49,9 @@ final class Network implements NetworkInterface, LoggerAwareInterface
     /**
      * Create a new instance.
      *
-     * @param CollectionInterface $collection The collection of devices on this network
+     * @param ?CollectionInterface $collection The collection of devices on this network
      */
-    public function __construct(CollectionInterface $collection = null)
+    public function __construct(?CollectionInterface $collection = null)
     {
         if ($collection === null) {
             $collection = new Discovery();
diff --git a/src/Playlist.php b/src/Playlist.php
index e1fc25f..aea6d06 100644
--- a/src/Playlist.php
+++ b/src/Playlist.php
@@ -90,7 +90,7 @@ protected function getNextPosition(): int
      *
      * @return void
      */
-    protected function addUris(array $tracks, int $position = null)
+    protected function addUris(array $tracks, ?int $position = null)
     {
         if ($position === null) {
             $position = $this->getNextPosition();
diff --git a/src/Queue.php b/src/Queue.php
index 086687b..d1396fb 100644
--- a/src/Queue.php
+++ b/src/Queue.php
@@ -43,9 +43,9 @@ class Queue implements QueueInterface
      * Create an instance of the Queue class.
      *
      * @param ControllerInterface $controller The Controller instance that this queue is for
-     * @param FactoryInterface $factory A factory to create tracks from
+     * @param ?FactoryInterface $factory A factory to create tracks from
      */
-    public function __construct(ControllerInterface $controller, FactoryInterface $factory = null)
+    public function __construct(ControllerInterface $controller, ?FactoryInterface $factory = null)
     {
         $this->id = "Q:0";
         $this->updateId = 0;
@@ -182,12 +182,12 @@ protected function getNextPosition(): int
      * Add multiple uris to the queue.
      *
      * @param UriInterface[] $tracks The track to add
-     * @param int $position The position to insert the track in the queue (zero-based),
+     * @param ?int $position The position to insert the track in the queue (zero-based),
      *                      by default the track will be added to the end of the queue
      *
      * @return void
      */
-    protected function addUris(array $tracks, int $position = null)
+    protected function addUris(array $tracks, ?int $position = null)
     {
         if ($position === null) {
             $position = $this->getNextPosition();
@@ -237,12 +237,12 @@ protected function addUris(array $tracks, int $position = null)
      * Add a track to the queue.
      *
      * @param string|UriInterface $track The URI of the track to add, or an object that implements the UriInterface
-     * @param int $position The position to insert the track in the queue (zero-based),
+     * @param ?int $position The position to insert the track in the queue (zero-based),
      *                      by default the track will be added to the end of the queue
      *
      * @return $this
      */
-    public function addTrack($track, int $position = null): QueueInterface
+    public function addTrack($track, ?int $position = null): QueueInterface
     {
         # If a simple uri has been passed then convert it to a Track instance
         if (is_string($track)) {
@@ -275,12 +275,12 @@ public function addTrack($track, int $position = null): QueueInterface
      *
      * @param string[]|UriInterface[] $tracks An array where each element is either the URI of the tracks to add,
      *                                          or an object that implements the UriInterface
-     * @param int $position The position to insert the tracks in the queue (zero-based),
+     * @param ?int $position The position to insert the tracks in the queue (zero-based),
      *                      by default the tracks will be added to the end of the queue
      *
      * @return $this
      */
-    public function addTracks(array $tracks, int $position = null): QueueInterface
+    public function addTracks(array $tracks, ?int $position = null): QueueInterface
     {
         $uris = [];
         foreach ($tracks as $track) {