diff --git a/hypervisor/boot/guest/vboot_info.c b/hypervisor/boot/guest/vboot_info.c
index ca8c262d0..27bcad211 100644
--- a/hypervisor/boot/guest/vboot_info.c
+++ b/hypervisor/boot/guest/vboot_info.c
@@ -271,7 +271,7 @@ static void init_vm_bootargs_info(struct acrn_vm *vm, const struct acrn_boot_inf
 
 	}
 
-	vm->sw.bootargs_info.size = strnlen_s((const char *)vm->sw.bootargs_info.src_addr, MAX_BOOTARGS_SIZE);
+	vm->sw.bootargs_info.size = strnlen_s((const char *)vm->sw.bootargs_info.src_addr, (MAX_BOOTARGS_SIZE - 1U)) + 1U;
 
 }