diff --git a/arch/sparc/kernel/ds.c b/arch/sparc/kernel/ds.c
index 62d6b15..4d9ac84 100644
--- a/arch/sparc/kernel/ds.c
+++ b/arch/sparc/kernel/ds.c
@@ -851,7 +851,7 @@
 
 		strcpy(full_boot_str, "boot ");
 		strlcpy(full_boot_str + strlen("boot "), boot_command,
-			sizeof(full_boot_str + strlen("boot ")));
+			sizeof(full_boot_str));
 		len = strlen(full_boot_str);
 
 		if (reboot_data_supported) {