@@ -119,6 +119,8 @@ public static function run(bool $isSetupPage = false): void
             return;
         }
 
+        $request = self::updateUriScheme($config, $request);
+
         if ($route !== '/messages') {
             try {
                 // Include session handling after the globals, to prevent overwriting.
@@ -647,4 +649,15 @@ private static function getGenericError(string $message): string
             'error_message' => $message,
         ]);
     }
+
+    private static function updateUriScheme(Config $config, ServerRequest $request): ServerRequest
+    {
+        $uriScheme = $config->isHttps() ? 'https' : 'http';
+        $uri = $request->getUri();
+        if ($uri->getScheme() === $uriScheme) {
+            return $request;
+        }
+
+        return $request->withUri($uri->withScheme($uriScheme));
+    }
 }
@@ -32,6 +32,7 @@
 use function ini_get;
 use function intval;
 use function is_array;
+use function is_bool;
 use function is_dir;
 use function is_int;
 use function is_numeric;
@@ -93,15 +94,10 @@ class Config
     /** @var mixed[] */
     public array $defaultServer = [];
 
-    private bool $isHttps;
+    private bool $isHttps = false;
 
     private Settings|null $config = null;
 
-    public function __construct()
-    {
-        $this->isHttps = $this->isHttps();
-    }
-
     /**
      * @param string|null $source source to read config from
      *
@@ -117,6 +113,7 @@ public function loadAndCheck(string|null $source = null): void
         // other settings, independent of config file, comes in
         $this->checkSystem();
 
+        $this->isHttps = $this->isHttps();
         $this->baseSettings = $this->settings;
     }
 
@@ -783,9 +780,10 @@ public function checkUploadSize(): void
      */
     public function isHttps(): bool
     {
+        /** @var mixed $isHttps */
         $isHttps = $this->get('is_https');
-        if ($isHttps !== null) {
-            return (bool) $isHttps;
+        if (is_bool($isHttps)) {
+            return $isHttps;
         }
 
         $url = $this->get('PmaAbsoluteUri');