diff --git a/bl1/bl1_private.h b/bl1/bl1_private.h
index 927c7b8..2cfeeea 100644
--- a/bl1/bl1_private.h
+++ b/bl1/bl1_private.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -19,11 +19,11 @@
 
 void bl1_prepare_next_image(unsigned int image_id);
 
-register_t bl1_fwu_smc_handler(unsigned int smc_fid,
-		register_t x1,
-		register_t x2,
-		register_t x3,
-		register_t x4,
+u_register_t bl1_fwu_smc_handler(unsigned int smc_fid,
+		u_register_t x1,
+		u_register_t x2,
+		u_register_t x3,
+		u_register_t x4,
 		void *cookie,
 		void *handle,
 		unsigned int flags);