diff --git a/arch/i386/kernel/efi.c b/arch/i386/kernel/efi.c
index c224c2aebbab15fb2137222d4bd36bc29574ed58..9202b67c4b2e5cc925b0670d0b3e804dc719abbc 100644
--- a/arch/i386/kernel/efi.c
+++ b/arch/i386/kernel/efi.c
@@ -361,7 +361,7 @@ void __init efi_init(void)
 	 */
 	c16 = (efi_char16_t *) boot_ioremap(efi.systab->fw_vendor, 2);
 	if (c16) {
-		for (i = 0; i < sizeof(vendor) && *c16; ++i)
+		for (i = 0; i < (sizeof(vendor) - 1) && *c16; ++i)
 			vendor[i] = *c16++;
 		vendor[i] = '\0';
 	} else