diff --git a/ndhc/dhcp.c b/ndhc/dhcp.c
index 32e4a12..e06f2c1 100644
--- a/ndhc/dhcp.c
+++ b/ndhc/dhcp.c
@@ -520,7 +520,7 @@ static int validate_dhcp_packet(struct client_state_t *cs, size_t len,
         return 0;
     }
     if (memcmp(packet->chaddr, client_config.arp, sizeof client_config.arp)) {
-        log_line("Packet client MAC %2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx does not equal our MAC %2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx.  Ignoring it.",
+        log_line("Packet client MAC %2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x does not equal our MAC %2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x.  Ignoring it.",
                  packet->chaddr[0], packet->chaddr[1], packet->chaddr[2],
                  packet->chaddr[3], packet->chaddr[4], packet->chaddr[5],
                  client_config.arp[0], client_config.arp[1],
diff --git a/ndhc/duiaid.c b/ndhc/duiaid.c
index 8575d6a..e902a7b 100644
--- a/ndhc/duiaid.c
+++ b/ndhc/duiaid.c
@@ -65,7 +65,7 @@ static void get_iaid_path(char *iaidfile, size_t ilen, uint8_t *hwaddr,
     }
     int splen = snprintf
         (iaidfile, ilen,
-         "%s/IAID-%2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx:%2.2hhx",
+         "%s/IAID-%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x",
          state_dir, hwaddr[0], hwaddr[1], hwaddr[2],
          hwaddr[3], hwaddr[4], hwaddr[5]);
     if (splen < 0) {