diff --git a/generator/src/Parameter.php b/generator/src/Parameter.php
index 5b89f78e..5caae117 100644
--- a/generator/src/Parameter.php
+++ b/generator/src/Parameter.php
@@ -10,15 +10,11 @@
 
 class Parameter
 {
-    /**
-     * @var PhpStanType
-     */
-    private $type;
+    private readonly PhpStanType $type;
 
     public function __construct(private \SimpleXMLElement $parameter, ?PhpStanFunction $phpStanFunction, int $position)
     {
         $phpStanParam = $phpStanFunction ? $phpStanFunction->getParameter($this->getParameterName(), $position) : null;
-        
         $this->type = $phpStanParam ? $phpStanParam->getType() : new PhpStanType($this->parameter->type->__toString()); //todo: is this if useful?
     }
 
diff --git a/generator/src/PhpStanFunctions/PhpStanFunction.php b/generator/src/PhpStanFunctions/PhpStanFunction.php
index 720240a6..47c8ead3 100644
--- a/generator/src/PhpStanFunctions/PhpStanFunction.php
+++ b/generator/src/PhpStanFunctions/PhpStanFunction.php
@@ -6,10 +6,7 @@
 
 class PhpStanFunction
 {
-    /**
-     * @var PhpStanType
-     */
-    private $returnType;
+    private readonly PhpStanType $returnType;
 
     /**
      * @var PhpStanParameter[]
@@ -24,6 +21,7 @@ public function __construct(array $signature)
         if (count($signature) < 1) {
             throw new \RuntimeException('Invalid signatures');
         }
+
         $this->returnType = new PhpStanType(\array_shift($signature));
         foreach ($signature as $name => $type) {
             $param = new PhpStanParameter($name, $type);
diff --git a/generator/src/PhpStanFunctions/PhpStanParameter.php b/generator/src/PhpStanFunctions/PhpStanParameter.php
index 26af3b77..a10c0c2c 100644
--- a/generator/src/PhpStanFunctions/PhpStanParameter.php
+++ b/generator/src/PhpStanFunctions/PhpStanParameter.php
@@ -8,8 +8,8 @@
 
 class PhpStanParameter
 {
-    private string $name;
-    private PhpStanType $type;
+    private readonly string $name;
+    private readonly PhpStanType $type;
 
     public function __construct(string $name, string $type)
     {
diff --git a/generator/src/WritePhpFunction.php b/generator/src/WritePhpFunction.php
index ca892539..b8c59009 100644
--- a/generator/src/WritePhpFunction.php
+++ b/generator/src/WritePhpFunction.php
@@ -93,19 +93,12 @@ private function writePhpFunction(): string
 
     private function generateExceptionCode(string $moduleName, Method $method) : string
     {
-        switch ($method->getErrorType()) {
-            case Method::FALSY_TYPE:
-                $errorValue = 'false';
-                break;
-            case Method::NULLSY_TYPE:
-                $errorValue = 'null';
-                break;
-            case Method::EMPTY_TYPE:
-                $errorValue = "''";
-                break;
-            default:
-                throw new \LogicException("Method doesn't have an error type");
-        }
+        $errorValue = match ($method->getErrorType()) {
+            Method::FALSY_TYPE => 'false',
+            Method::NULLSY_TYPE => 'null',
+            Method::EMPTY_TYPE => "''",
+            default => throw new \LogicException("Method doesn't have an error type"),
+        };
 
         // Special case for CURL: we need the first argument of the method if this is a resource.
         if ($moduleName === 'Curl') {