diff --git a/src/kit/taosnetwork/client.c b/src/kit/taosnetwork/client.c
index 9f51f55d93986abf9d1a1c92913093223cf4b1d5..4b72c5c8598710501ced9e7c86cc51250a91e592 100644
--- a/src/kit/taosnetwork/client.c
+++ b/src/kit/taosnetwork/client.c
@@ -66,9 +66,9 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
     case 'l':
       arguments->pktLen = atoi(arg);
       break;
+
     default:
-      printf("unknow parameter!\n");
-      break;
+      return ARGP_ERR_UNKNOWN;
   }
   return 0;
 }
diff --git a/src/kit/taosnetwork/server.c b/src/kit/taosnetwork/server.c
index 403faec91b6aa8dbbc00897658930d8dccb0a144..1c3bc6fa098d793c2c7d1c355c524c755301b57b 100644
--- a/src/kit/taosnetwork/server.c
+++ b/src/kit/taosnetwork/server.c
@@ -66,8 +66,9 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
     case 'l':
       arguments->pktLen = atoi(arg);
       break;
+
     default:
-      break;
+      return ARGP_ERR_UNKNOWN;
   }
   return 0;
 }