diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fca2e98..2148426 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,7 @@ jobs:
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
       with:
-        php-version: '8.2'
+        php-version: '8.4'
     - name: Install composer dependencies
       run: composer require "illuminate/support:^${{ matrix.laravel }}.0"
     - name: Run tests
@@ -38,7 +38,7 @@ jobs:
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
       with:
-        php-version: '8.2'
+        php-version: '8.4'
     - name: Install composer dependencies
       run: composer install
     - name: Run phpstan
@@ -52,7 +52,7 @@ jobs:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.2'
+          php-version: '8.3'
       - name: Install php-cs-fixer
         run: composer global require friendsofphp/php-cs-fixer
       - name: Run php-cs-fixer
diff --git a/phpstan.neon b/phpstan.neon
index e064b98..2d7efab 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -22,5 +22,4 @@ parameters:
             message: '#Unsafe usage of new static#'
             paths:
                 - src/Currency.php
-
-    checkMissingIterableValueType: false
+        - identifier: missingType.iterableValue
diff --git a/src/Currency.php b/src/Currency.php
index c2db2a4..3c80aa9 100644
--- a/src/Currency.php
+++ b/src/Currency.php
@@ -46,17 +46,17 @@ class Currency implements Arrayable, JsonSerializable
 
     /** Create a new Currency instance. */
     public function __construct(
-        string $code = null,
-        string $name = null,
-        float $rate = null,
-        string $prefix = null,
-        string $suffix = null,
-        int $mathDecimals = null,
-        int $displayDecimals = null,
-        int $rounding = null,
-        string $decimalSeparator = null,
-        string $thousandsSeparator = null,
-        bool $trimTrailingDecimalZeros = null,
+        ?string $code = null,
+        ?string $name = null,
+        ?float $rate = null,
+        ?string $prefix = null,
+        ?string $suffix = null,
+        ?int $mathDecimals = null,
+        ?int $displayDecimals = null,
+        ?int $rounding = null,
+        ?string $decimalSeparator = null,
+        ?string $thousandsSeparator = null,
+        ?bool $trimTrailingDecimalZeros = null,
     ) {
         $this->code = $code ?? $this->code ?? '';
         $this->name = $name ?? $this->name ?? '';
diff --git a/src/Exceptions/InvalidCurrencyException.php b/src/Exceptions/InvalidCurrencyException.php
index 8b0e7b4..d705cfa 100644
--- a/src/Exceptions/InvalidCurrencyException.php
+++ b/src/Exceptions/InvalidCurrencyException.php
@@ -8,7 +8,7 @@
 
 class InvalidCurrencyException extends Exception
 {
-    public function __construct(string $message = null)
+    public function __construct(?string $message = null)
     {
         parent::__construct($message ?? 'The currency is invalid');
     }
diff --git a/src/Money.php b/src/Money.php
index 6eaa6a7..b8f5f6f 100644
--- a/src/Money.php
+++ b/src/Money.php
@@ -15,7 +15,7 @@ final class Money implements JsonSerializable, Arrayable, Wireable
     protected Currency $currency;
 
     /** Create a new Money instance. */
-    public function __construct(int $value, Currency|string $currency = null)
+    public function __construct(int $value, Currency|string|null $currency = null)
     {
         $this->value = $value;
         $this->currency = currency($currency);
@@ -34,7 +34,7 @@ protected function newFromDecimal(float $decimal): self
     }
 
     /** Create a Money instance from a decimal value. */
-    public static function fromDecimal(float $decimal, Currency|string $currency = null): self
+    public static function fromDecimal(float $decimal, Currency|string|null $currency = null): self
     {
         return new static(
             (int) round($decimal * pow(10, currency($currency)->mathDecimals())),
@@ -179,7 +179,7 @@ public function rawFormatted(mixed ...$overrides): string
      * @param  Currency|string|null  $currency The currency to use when passing the overrides. If not provided, the currency of the formatted string is used.
      * @param  array  ...$overrides The overrides used when formatting the money instance.
      */
-    public static function fromFormatted(string $formatted, Currency|string $currency = null, mixed ...$overrides): self
+    public static function fromFormatted(string $formatted, Currency|string|null $currency = null, mixed ...$overrides): self
     {
         $currency = isset($currency)
             ? currency($currency)
@@ -277,7 +277,7 @@ public function toDefault(): self
     }
 
     /** Round the Money to a custom precision. */
-    public function rounded(int $precision = null): self
+    public function rounded(?int $precision = null): self
     {
         $precision ??= $this->currency->rounding();
 
diff --git a/src/helpers.php b/src/helpers.php
index 9fa6f61..d2f2764 100644
--- a/src/helpers.php
+++ b/src/helpers.php
@@ -8,7 +8,7 @@
 
 if (! function_exists('money')) {
     /** Create a Money instance. */
-    function money(int $amount, Currency|string $currency = null): Money
+    function money(int $amount, Currency|string|null $currency = null): Money
     {
         return new Money($amount, $currency ?? currencies()->getDefault());
     }
@@ -16,7 +16,7 @@ function money(int $amount, Currency|string $currency = null): Money
 
 if (! function_exists('currency')) {
     /** Fetch a currency. If no argument is provided, the current currency will be returned. */
-    function currency(Currency|string $currency = null): Currency
+    function currency(Currency|string|null $currency = null): Currency
     {
         if ($currency) {
             return $currency instanceof Currency