diff --git a/adafruit_wiznet5k/adafruit_wiznet5k.py b/adafruit_wiznet5k/adafruit_wiznet5k.py
index cba2beb..a3b0d77 100644
--- a/adafruit_wiznet5k/adafruit_wiznet5k.py
+++ b/adafruit_wiznet5k/adafruit_wiznet5k.py
@@ -598,6 +598,7 @@ def socket_open(self, socket_num, conn_mode=SNMR_TCP):
             SNSR_SOCK_FIN_WAIT,
             SNSR_SOCK_CLOSE_WAIT,
             SNSR_SOCK_CLOSING,
+            SNSR_SOCK_UDP,
         ):
             if self._debug:
                 print("* Opening W5k Socket, protocol={}".format(conn_mode))