diff --git a/config/amfcfg.yaml b/config/amfcfg.yaml
index 37dbeb0e..1750bed0 100644
--- a/config/amfcfg.yaml
+++ b/config/amfcfg.yaml
@@ -90,6 +90,11 @@ configuration:
     enable: true     # true or false
     expireTime: 6s   # default is 6 seconds
     maxRetryTimes: 4 # the max number of retransmission
+  # retransmission timer for NAS Configuration Update Command message
+  t3555:
+    enable: true     # true or false
+    expireTime: 6s   # default is 6 seconds
+    maxRetryTimes: 4 # the max number of retransmissio
   # retransmission timer for NAS Authentication Request/Security Mode Command message
   t3560:
     enable: true     # true or false