diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 3115caa7d7d0..1b98f8c12b96 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -33,7 +33,7 @@ static union uvh_apicid		uvh_apicid;
 static int			uv_node_id;
 
 /* Unpack AT/OEM/TABLE ID's to be NULL terminated strings */
-static u8 uv_archtype[UV_AT_SIZE];
+static u8 uv_archtype[UV_AT_SIZE + 1];
 static u8 oem_id[ACPI_OEM_ID_SIZE + 1];
 static u8 oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
 
@@ -320,7 +320,7 @@ static int __init decode_arch_type(unsigned long ptr)
 
 	if (n > 0 && n < sizeof(uv_ate->archtype)) {
 		pr_info("UV: UVarchtype received from BIOS\n");
-		uv_stringify(UV_AT_SIZE, uv_archtype, uv_ate->archtype);
+		uv_stringify(sizeof(uv_archtype), uv_archtype, uv_ate->archtype);
 		return 1;
 	}
 	return 0;
@@ -378,7 +378,7 @@ static int __init uv_set_system_type(char *_oem_id, char *_oem_table_id)
 	if (!early_get_arch_type())
 
 		/* If not use OEM ID for UVarchtype */
-		uv_stringify(UV_AT_SIZE, uv_archtype, _oem_id);
+		uv_stringify(sizeof(uv_archtype), uv_archtype, oem_id);
 
 	/* Check if not hubbed */
 	if (strncmp(uv_archtype, "SGI", 3) != 0) {