diff --git a/realm/include/realm_rsi.h b/realm/include/realm_rsi.h
index c7ea5a5..e9b6ce8 100644
--- a/realm/include/realm_rsi.h
+++ b/realm/include/realm_rsi.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Arm Limited. All rights reserved.
+ * Copyright (c) 2022-2023, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  *
@@ -77,7 +77,7 @@
  * ret1 == Top of modified IPA range
  */
 
-#define RSI_HOST_CALL_NR_GPRS		7U
+#define RSI_HOST_CALL_NR_GPRS		31U
 
 struct rsi_host_call {
 	SET_MEMBER(struct {
@@ -89,7 +89,7 @@
 };
 
 /*
- * arg0 == struct rsi_host_call addr
+ * arg0 == struct rsi_host_call address
  */
 #define RSI_HOST_CALL		SMC_RSI_FID(9U)