diff --git a/psalm.xml b/psalm.xml
index 967944d..8f08fd5 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -14,10 +14,6 @@
         </ignoreFiles>
     </projectFiles>
     <issueHandlers>
-        <UndefinedAttributeClass>
-            <errorLevel type="suppress">
-                <referencedClass name="JetBrains\PhpStorm\ExpectedValues" />
-            </errorLevel>
-        </UndefinedAttributeClass>
+        <ClassMustBeFinal errorLevel="suppress" />
     </issueHandlers>
 </psalm>
diff --git a/src/Composer/Package.php b/src/Composer/Package.php
index f2824c8..bec0ec1 100644
--- a/src/Composer/Package.php
+++ b/src/Composer/Package.php
@@ -13,14 +13,20 @@ final class Package implements PackageInterface
      * @param non-empty-string $packageName
      * @return non-empty-string[]
      */
+    #[\Override]
     public function getRequiredVersions(string $packageName): array
     {
         $versions = [];
         foreach (InstalledVersions::getInstalledPackages() as $package) {
             $path = InstalledVersions::getInstallPath($package);
             if ($path !== null && \file_exists($path . '/composer.json')) {
+                $content = \file_get_contents($path . '/composer.json');
+                if ($content === false) {
+                    continue;
+                }
+
                 /** @var array{require?: array<non-empty-string, non-empty-string>} $composerJson */
-                $composerJson = \json_decode(\file_get_contents($path . '/composer.json'), true);
+                $composerJson = \json_decode($content, true);
 
                 if (
                     isset($composerJson['require'][$packageName]) &&
diff --git a/src/Environment/Native.php b/src/Environment/Native.php
index 53daee7..bf3fe32 100644
--- a/src/Environment/Native.php
+++ b/src/Environment/Native.php
@@ -15,6 +15,7 @@ public function __construct(
     /**
      * @param non-empty-string $name
      */
+    #[\Override]
     public function get(string $name, mixed $default = null): mixed
     {
         return $this->values[$name] ?? $default;
diff --git a/src/Process/Process.php b/src/Process/Process.php
index 1d88c16..c987e40 100644
--- a/src/Process/Process.php
+++ b/src/Process/Process.php
@@ -8,6 +8,7 @@
 
 final class Process implements ProcessInterface
 {
+    #[\Override]
     public function exec(array $command): string
     {
         $process = new \Symfony\Component\Process\Process($command);
diff --git a/src/Process/ProcessInterface.php b/src/Process/ProcessInterface.php
index b466461..12c32d9 100644
--- a/src/Process/ProcessInterface.php
+++ b/src/Process/ProcessInterface.php
@@ -6,5 +6,8 @@
 
 interface ProcessInterface
 {
+    /**
+     * @param array<string> $command
+     */
     public function exec(array $command): string;
 }
diff --git a/src/Version/Comparator.php b/src/Version/Comparator.php
index c35ad8d..d3ea566 100644
--- a/src/Version/Comparator.php
+++ b/src/Version/Comparator.php
@@ -47,6 +47,7 @@ public static function compare(string $a, string $b): int
      * @param non-empty-string $requested
      * @param non-empty-string $installed
      */
+    #[\Override]
     public function greaterThan(string $requested, string $installed): bool
     {
         return self::compare($this->parser->normalize($installed), $this->parser->normalize($requested)) >= 0;
@@ -56,6 +57,7 @@ public function greaterThan(string $requested, string $installed): bool
      * @param non-empty-string $requested
      * @param non-empty-string $installed
      */
+    #[\Override]
     public function lessThan(string $requested, string $installed): bool
     {
         return self::compare($this->parser->normalize($installed), $this->parser->normalize($requested)) <= 0;
@@ -65,6 +67,7 @@ public function lessThan(string $requested, string $installed): bool
      * @param non-empty-string $requested
      * @param non-empty-string $installed
      */
+    #[\Override]
     public function equal(string $requested, string $installed): bool
     {
         return self::compare($this->parser->normalize($installed), $this->parser->normalize($requested)) === 0;
diff --git a/src/Version/Installed.php b/src/Version/Installed.php
index 89d3645..8aa63e5 100644
--- a/src/Version/Installed.php
+++ b/src/Version/Installed.php
@@ -40,17 +40,18 @@ public function __construct(
      *
      * @throws RoadrunnerNotInstalledException
      */
+    #[\Override]
     public function getInstalledVersion(): string
     {
-        if (!empty(self::$cachedVersion)) {
+        if (self::$cachedVersion !== null) {
             return self::$cachedVersion;
         }
 
-        if (!empty(self::$cachedVersion = $this->getVersionFromEnv())) {
+        if ((self::$cachedVersion = $this->getVersionFromEnv()) !== null) {
             return self::$cachedVersion;
         }
 
-        if (!empty(self::$cachedVersion = $this->getVersionFromConsoleCommand())) {
+        if ((self::$cachedVersion = $this->getVersionFromConsoleCommand()) !== null) {
             return self::$cachedVersion;
         }
 
diff --git a/src/Version/Required.php b/src/Version/Required.php
index cf0e7f4..2b6a862 100644
--- a/src/Version/Required.php
+++ b/src/Version/Required.php
@@ -26,6 +26,7 @@ public function __construct(?PackageInterface $package = null)
     /**
      * @return non-empty-string|null
      */
+    #[\Override]
     public function getRequiredVersion(): ?string
     {
         if (self::$cachedVersion !== null) {
diff --git a/src/VersionChecker.php b/src/VersionChecker.php
index 66534df..86e2eee 100644
--- a/src/VersionChecker.php
+++ b/src/VersionChecker.php
@@ -31,7 +31,7 @@ public function __construct(
     }
 
     /**
-     * @param non-empty-string|null $version
+     * @param string|null $version Null or an empty string takes the version from the installed packages.
      *
      * @throws UnsupportedVersionException
      * @throws RoadrunnerNotInstalledException
@@ -39,11 +39,11 @@ public function __construct(
      */
     public function greaterThan(?string $version = null): void
     {
-        if (empty($version)) {
+        if ($version === null || $version === '') {
             $version = $this->requiredVersion->getRequiredVersion();
         }
 
-        if (empty($version)) {
+        if ($version === null) {
             throw new RequiredVersionException(
                 'Unable to determine required RoadRunner version.' .
                 ' Please specify the required version in the `$version` parameter.',
@@ -108,9 +108,7 @@ public function equal(string $version): void
      */
     private function getFormattedMessage(string $message, string $installedVersion, string $version): string
     {
-        \preg_match('/\bv?(\d+)\.(\d+)\.(\d+)\b/', $version, $matches);
-
-        if (!empty($matches[0])) {
+        if (\preg_match('/\bv?(\d+)\.(\d+)\.(\d+)\b/', $version, $matches) === 1) {
             $version = $matches[1] . '.' . $matches[2] . '.' . $matches[3];
         }