diff --git a/payloads/coreinfo/coreboot_module.c b/payloads/coreinfo/coreboot_module.c
index d33ea9ee60..77a4bb2d8b 100644
--- a/payloads/coreinfo/coreboot_module.c
+++ b/payloads/coreinfo/coreboot_module.c
@@ -142,8 +142,8 @@ static void parse_mainboard(unsigned char *ptr)
 {
 	struct cb_mainboard *mb = (struct cb_mainboard *)ptr;
 
-	strncpy(cb_info.vendor, cb_mb_vendor_part(mb), 31);
-	strncpy(cb_info.part, cb_mb_part_string(mb), 31);
+	strncpy(cb_info.vendor, cb_mb_vendor_part(mb), sizeof(cb_info.vendor) - 1);
+	strncpy(cb_info.part, cb_mb_part_string(mb), sizeof(cb_info.part) - 1);
 }
 
 static void parse_strings(unsigned char *ptr)