diff --git a/composer.json b/composer.json
index 806298b..40e8e25 100644
--- a/composer.json
+++ b/composer.json
@@ -22,16 +22,16 @@
         "ext-bcmath": "*",
         "doctrine/dbal": "^4",
         "moneyphp/money": "^4.0.3",
-        "thecodingmachine/safe": "^1.3|^2"
+        "thecodingmachine/safe": "^3.0"
     },
     "require-dev": {
         "doctrine/coding-standard": "^12.0",
-        "phpstan/phpstan": "^1.12",
+        "phpstan/phpstan": "^2.1",
         "phpunit/phpunit": "^10.5",
         "roave/no-floaters": "^1.11",
         "squizlabs/php_codesniffer": "^3.10",
-        "thecodingmachine/phpstan-safe-rule": "^1.1|^1.2",
-        "vimeo/psalm": "^5.26"
+        "thecodingmachine/phpstan-safe-rule": "^1.4",
+        "vimeo/psalm": "^6.15"
     },
     "minimum-stability": "stable",
     "config": {
diff --git a/src/Bitcoin.php b/src/Bitcoin.php
index 4a939a5..9eadf12 100644
--- a/src/Bitcoin.php
+++ b/src/Bitcoin.php
@@ -6,19 +6,23 @@
 
 use Money\Currencies;
 use Money\Currencies\BitcoinCurrencies;
+use Override;
 
-class Bitcoin extends BaseMoney
+final class Bitcoin extends BaseMoney
 {
+    #[Override]
     public static function humanReadableName(): string
     {
         return 'Bitcoin';
     }
 
+    #[Override]
     protected static function classSubunits(): int
     {
         return 8;
     }
 
+    #[Override]
     protected static function getAllowedCurrencies(): Currencies
     {
         return new BitcoinCurrencies();
diff --git a/src/Currency.php b/src/Currency.php
index a610030..b70e5c5 100644
--- a/src/Currency.php
+++ b/src/Currency.php
@@ -7,36 +7,37 @@
 use Money\Currencies;
 use Money\Currency as LibCurrency;
 
+/** @psalm-api */
 class Currency
 {
     /** @psalm-param  non-empty-string $code */
-    final private function __construct(private string $code)
+    final protected function __construct(private string $code)
     {
     }
 
     /** @psalm-param  non-empty-string $code */
-    final public static function create(string $code): self
+    public static function create(string $code): self
     {
         return new static($code);
     }
 
     /** @psalm-return non-empty-string */
-    final public function getCode(): string
+    public function getCode(): string
     {
         return $this->getLibCurrency()->getCode();
     }
 
-    final public function equals(self $other): bool
+    public function equals(self $other): bool
     {
         return $this->getLibCurrency()->equals($other->getLibCurrency());
     }
 
-    final public function isAvailableWithin(Currencies $currencies): bool
+    public function isAvailableWithin(Currencies $currencies): bool
     {
         return $currencies->contains($this->getLibCurrency());
     }
 
-    final public function jsonSerialize(): string
+    public function jsonSerialize(): string
     {
         return $this->getLibCurrency()->jsonSerialize();
     }
diff --git a/src/GaapMoney.php b/src/GaapMoney.php
index b286742..e4a60ee 100644
--- a/src/GaapMoney.php
+++ b/src/GaapMoney.php
@@ -6,14 +6,17 @@
 
 use Money\Currencies;
 use Money\Currencies\ISOCurrencies;
+use Override;
 
-class GaapMoney extends BaseMoney
+final class GaapMoney extends BaseMoney
 {
+    #[Override]
     protected static function classSubunits(): int
     {
         return 4;
     }
 
+    #[Override]
     protected static function getAllowedCurrencies(): Currencies
     {
         return new ISOCurrencies();
diff --git a/src/Money.php b/src/Money.php
index 0fc617d..8b262d3 100644
--- a/src/Money.php
+++ b/src/Money.php
@@ -7,16 +7,20 @@
 use Money\Currencies;
 use Money\Currencies\CurrencyList;
 use Money\Currencies\ISOCurrencies;
+use Override;
 
+/** @psalm-api */
 class Money extends BaseMoney
 {
     private static Currencies|null $currencies = null;
 
+    #[Override]
     protected static function classSubunits(): int
     {
         return 2;
     }
 
+    #[Override]
     protected static function getAllowedCurrencies(): Currencies
     {
         if (self::$currencies !== null) {
@@ -41,7 +45,7 @@ private static function initializeCurrencies(): Currencies
             $twoOrLessSubUnitCurrencies[$currency->getCode()] = $subUnit;
         }
 
-        /** @psalm-var array<non-empty-string, positive-int|0> $twoOrLessSubUnitCurrencies */
+        /** @psalm-var array<non-empty-string, int<0, 2>> $twoOrLessSubUnitCurrencies */
         $currencies = new CurrencyList($twoOrLessSubUnitCurrencies);
 
         self::$currencies = $currencies;
diff --git a/src/Type/BTCMoneyType.php b/src/Type/BTCMoneyType.php
index bee6dae..c99c9dd 100644
--- a/src/Type/BTCMoneyType.php
+++ b/src/Type/BTCMoneyType.php
@@ -6,16 +6,18 @@
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
 use Doctrine\DBAL\Types\Type;
+use Override;
 
 use function array_merge;
 use function bcdiv;
 use function bcmul;
 
-class BTCMoneyType extends Type
+final class BTCMoneyType extends Type
 {
     public const TYPE_NAME = 'btc_money';
 
     /** @param mixed[] $column */
+    #[Override]
     public function getSQLDeclaration(array $column, AbstractPlatform $platform): string
     {
         return $platform->getDecimalTypeDeclarationSQL(
@@ -29,6 +31,7 @@ public function getSQLDeclaration(array $column, AbstractPlatform $platform): st
         );
     }
 
+    #[Override]
     public function convertToPHPValue(mixed $value, AbstractPlatform $platform): string|null
     {
         if ($value === null) {
@@ -41,6 +44,7 @@ public function convertToPHPValue(mixed $value, AbstractPlatform $platform): str
         return bcmul($value, '100000000', 0);
     }
 
+    #[Override]
     public function convertToDatabaseValue(mixed $value, AbstractPlatform $platform): string|null
     {
         if ($value === null) {
diff --git a/src/Type/CurrencyType.php b/src/Type/CurrencyType.php
index eac596a..efe5041 100644
--- a/src/Type/CurrencyType.php
+++ b/src/Type/CurrencyType.php
@@ -6,14 +6,16 @@
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
 use Doctrine\DBAL\Types\Type;
+use Override;
 
 use function array_merge;
 
-class CurrencyType extends Type
+final class CurrencyType extends Type
 {
     public const TYPE_NAME = 'currency';
 
     /** @param mixed[] $column */
+    #[Override]
     public function getSQLDeclaration(array $column, AbstractPlatform $platform): string
     {
         return $platform->getStringTypeDeclarationSQL(
diff --git a/src/Type/GaapMoneyType.php b/src/Type/GaapMoneyType.php
index 419b7cc..d666d5e 100644
--- a/src/Type/GaapMoneyType.php
+++ b/src/Type/GaapMoneyType.php
@@ -6,16 +6,18 @@
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
 use Doctrine\DBAL\Types\Type;
+use Override;
 
 use function array_merge;
 use function bcdiv;
 use function bcmul;
 
-class GaapMoneyType extends Type
+final class GaapMoneyType extends Type
 {
     public const TYPE_NAME = 'gaap_money';
 
     /** @param mixed[] $column */
+    #[Override]
     public function getSQLDeclaration(array $column, AbstractPlatform $platform): string
     {
         return $platform->getDecimalTypeDeclarationSQL(
@@ -29,6 +31,7 @@ public function getSQLDeclaration(array $column, AbstractPlatform $platform): st
         );
     }
 
+    #[Override]
     public function convertToPHPValue(mixed $value, AbstractPlatform $platform): string|null
     {
         if ($value === null) {
@@ -41,6 +44,7 @@ public function convertToPHPValue(mixed $value, AbstractPlatform $platform): str
         return bcmul($value, '10000', 0);
     }
 
+    #[Override]
     public function convertToDatabaseValue(mixed $value, AbstractPlatform $platform): string|null
     {
         if ($value === null) {
diff --git a/src/Type/MoneyType.php b/src/Type/MoneyType.php
index cc5120e..5a7cd75 100644
--- a/src/Type/MoneyType.php
+++ b/src/Type/MoneyType.php
@@ -6,16 +6,18 @@
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
 use Doctrine\DBAL\Types\Type;
+use Override;
 
 use function array_merge;
 use function bcdiv;
 use function bcmul;
 
-class MoneyType extends Type
+final class MoneyType extends Type
 {
     public const TYPE_NAME = 'money';
 
     /** @param mixed[] $column */
+    #[Override]
     public function getSQLDeclaration(array $column, AbstractPlatform $platform): string
     {
         return $platform->getDecimalTypeDeclarationSQL(
@@ -29,6 +31,7 @@ public function getSQLDeclaration(array $column, AbstractPlatform $platform): st
         );
     }
 
+    #[Override]
     public function convertToPHPValue(mixed $value, AbstractPlatform $platform): string|null
     {
         if ($value === null) {
@@ -41,6 +44,7 @@ public function convertToPHPValue(mixed $value, AbstractPlatform $platform): str
         return bcmul($value, '100', 0);
     }
 
+    #[Override]
     public function convertToDatabaseValue(mixed $value, AbstractPlatform $platform): string|null
     {
         if ($value === null) {