diff --git a/main.cpp b/main.cpp
index 60fe327..e4cf1cb 100644
--- a/main.cpp
+++ b/main.cpp
@@ -66,9 +66,9 @@ static void print_help()
     printf("    --delay-capacity      <number>        max number of delayed packets, 0 means unlimited, default: 0\n");
 	printf("    --disable-fec         <number>        completely disable fec, turn the program into a normal udp tunnel\n");
 	printf("    --sock-buf            <number>        buf size for socket, >=10 and <=10240, unit: kbyte, default: 1024\n");
-	printf("    --out-addr            ip:port         force all output packets to go through this address. Set port to 0 to use a random one.\n");
+	printf("    --out-addr            ip:port         force all output packets of '-r' end to go through this address, port 0 for random port.\n");
 #ifdef __linux__
-	printf("    --out-interface       <string>        force all output packets to go through this interface.\n");
+	printf("    --out-interface       <string>        force all output packets of '-r' end to go through this interface.\n");
 #endif
 	printf("log and help options:\n");
 	printf("    --log-level           <number>        0: never    1: fatal   2: error   3: warn \n");
diff --git a/misc.cpp b/misc.cpp
index b165b89..e9715d8 100644
--- a/misc.cpp
+++ b/misc.cpp
@@ -723,7 +723,7 @@ void process_arg(int argc, char *argv[])
 
 
 	int no_l = 1, no_r = 1;
-	while ((opt = getopt_long(argc, argv, "l:r:hcsk:j:f:p:n:i:q:b",long_options,&option_index)) != -1)
+	while ((opt = getopt_long(argc, argv, "l:r:hcsk:j:f:p:n:i:q:",long_options,&option_index)) != -1)
 	{
 		//string opt_key;
 		//opt_key+=opt;