thodg/cgminer

diff --git a/driver-hashfast.c b/driver-hashfast.c
index 52fe825..d99ab0e 100644
--- a/driver-hashfast.c
+++ b/driver-hashfast.c
@@ -1167,8 +1167,7 @@ static struct api_data *hfa_api_stats(struct cgpu_info *cgpu)
 	root = api_add_string(root, "firmware rev", buf, true);
 	sprintf(buf, "%d.%d", (db->hardware_rev >> 8) & 0xff, db->hardware_rev & 0xff);
 	root = api_add_string(root, "hardware rev", buf, true);
-	varint = db->serial_number;
-	root = api_add_int(root, "serial number", &varint, true);
+	root = api_add_hex32(root, "serial number", &db->serial_number, true);
 	varint = db->hash_clockrate;
 	root = api_add_int(root, "hash clockrate", &varint, true);
 	varint = db->inflight_target;