diff --git a/targets/corstone-300/uart.c b/targets/corstone-300/uart.c
index cba54d8..bd7dddf 100644
--- a/targets/corstone-300/uart.c
+++ b/targets/corstone-300/uart.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2020 Arm Limited. All rights reserved.
+ * Copyright (c) 2019-2021 Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: Apache-2.0
  *
@@ -131,6 +131,7 @@
             lp++;  /* increment line pointer         */
             cnt++; /* and count                      */
             c = LF;
+            __attribute__((fallthrough)); /* intentional fallthrough */
         default:
             uart_putc(*lp = c); /* echo and store character       */
             fflush(stdout);