diff --git a/drivers/soc/qcom/smd-rpm.c b/drivers/soc/qcom/smd-rpm.c
index 413f9f4ae9cd..125cb456a5dc 100644
--- a/drivers/soc/qcom/smd-rpm.c
+++ b/drivers/soc/qcom/smd-rpm.c
@@ -75,7 +75,7 @@ struct qcom_rpm_message {
 	__le32 length;
 	union {
 		__le32 msg_id;
-		u8 message[0];
+		DECLARE_FLEX_ARRAY(u8, message);
 	};
 };