diff --git a/lib/SimpleSAML/SessionHandlerPHP.php b/lib/SimpleSAML/SessionHandlerPHP.php
index cd19d3bde0df9cb8c3f00d2370aeb7d6e8857402..a580e662a7e48b08a37c1edb94a5bbfe5014c3d0 100644
--- a/lib/SimpleSAML/SessionHandlerPHP.php
+++ b/lib/SimpleSAML/SessionHandlerPHP.php
@@ -77,6 +77,8 @@ class SessionHandlerPHP extends SessionHandler
         $params = $this->getCookieParams();
 
         if (!headers_sent()) {
+            session_name($this->cookie_name);
+
             /** @psalm-suppress InvalidArgument */
             session_set_cookie_params([
                 'lifetime' => $params['lifetime'],