diff --git a/composer.json b/composer.json
index dbb1417..b996cc2 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,7 @@
     "support": {
         "issues": "https://github.com/opencultureconsulting/oai-pmh2/issues",
         "source": "https://github.com/opencultureconsulting/oai-pmh2",
-        "docs": "https://github.com/opencultureconsulting/oai-pmh2/blob/main/README.md"
+        "docs": "https://opencultureconsulting.github.io/oai-pmh2/"
     },
     "require": {
         "php": "^8.1",
@@ -61,8 +61,8 @@
     },
     "scripts": {
         "pre-install-cmd": [
-            "@php -r \"!is_dir('./data') && mkdir('./data', 0775);\"",
-            "@php -r \"!file_exists('./config/config.yml') && copy('./config/config.dist.yml', './config/config.yml');\""
+            "@php -r \"if (!is_dir('./data')) { mkdir('./data', 0775); }\"",
+            "@php -r \"if (!file_exists('./config/config.yml')) { copy('./config/config.dist.yml', './config/config.yml'); }\""
         ],
         "post-install-cmd": [
             "@doctrine:clear-cache --quiet",
diff --git a/public/index.php b/public/index.php
index ca81279..eec4d35 100644
--- a/public/index.php
+++ b/public/index.php
@@ -24,5 +24,4 @@ namespace OCC\OaiPmh2;
 
 require __DIR__ . '/../vendor/autoload.php';
 
-$app = new App();
-$app->run();
+(new App())->run();
diff --git a/src/Middleware.php b/src/Middleware.php
index c62f870..10e8c56 100644
--- a/src/Middleware.php
+++ b/src/Middleware.php
@@ -77,4 +77,11 @@ abstract class Middleware extends AbstractMiddleware
         }
         return $response;
     }
+
+    final public function __construct()
+    {
+        // Make constructor final to avoid issues in dispatcher.
+        // @see https://psalm.dev/229
+    }
+
 }
diff --git a/src/Middleware/Dispatcher.php b/src/Middleware/Dispatcher.php
index 04f39d9..1259088 100644
--- a/src/Middleware/Dispatcher.php
+++ b/src/Middleware/Dispatcher.php
@@ -88,9 +88,10 @@ class Dispatcher extends AbstractMiddleware
         if (!ErrorHandler::getInstance()->hasErrors()) {
             /** @var string */
             $verb = $request->getAttribute('verb');
-            /** @var Middleware $middleware */
             $middleware = __NAMESPACE__ . '\\' . $verb;
-            $this->requestHandler->queue->enqueue(new $middleware());
+            if (is_a($middleware, Middleware::class, true)) {
+                $this->requestHandler->queue->enqueue(new $middleware());
+            }
         }
         $this->requestHandler->queue->enqueue(ErrorHandler::getInstance());
         return $request;