diff --git a/pppr_cookie.php b/pppr_cookie.php
index 48c233f..d35c7d2 100644
--- a/pppr_cookie.php
+++ b/pppr_cookie.php
@@ -40,11 +40,13 @@ function set_pppr_cookie($is_local, $street_name, $house_number, $postcode, $cit
     $signature = hash_hmac('sha256', $data_string, WP_PPPR_SALT);
     $cookie_value = $data_string . "|" . $signature;
 
+    $is_secure = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off');
+
     setcookie("PPPR", $cookie_value, [
         'expires' => time() + 7200,
         'path' => '/',
         'domain' => $_SERVER['SERVER_NAME'],
-        'secure' => true,   // Only send over HTTPS
+        'secure' => $is_secure,   // Only send over HTTPS
         'httponly' => true, // Prevent JavaScript access
         'samesite' => 'Lax' // Protect against CSRF
     ]);