diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 458bb1280ebf..5b97e420a95f 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -288,7 +288,7 @@ struct mxser_board {
 	enum mxser_must_hwid must_hwid;
 	speed_t max_baud;
 
-	struct mxser_port ports[] __counted_by(nports);
+	struct mxser_port ports[] /* __counted_by(nports) */;
 };
 
 static DECLARE_BITMAP(mxser_boards, MXSER_BOARDS);