diff --git a/README.md b/README.md
index 58dc19a..696486d 100644
--- a/README.md
+++ b/README.md
@@ -62,7 +62,7 @@ After it is connected and logged in:
   To use this with for example [WSJT-X](https://physics.princeton.edu/pulsar/K1JT/wsjtx.html),
   open WSJT-X settings, go to the *Radio* tab, set the *rig type* to `Hamlib
   NET rigctl`, and the *Network server* to `localhost`.
-- Starts a **TCP server** on port `4533` for exposing the **serial port**.
+- Starts a **TCP server** on port `4531` for exposing the **serial port**.
   This can be used for an externally launched `rigctld` for example.
 
 ### Virtual serial port
diff --git a/args.go b/args.go
index 62c0e08..09d4644 100644
--- a/args.go
+++ b/args.go
@@ -27,7 +27,7 @@ func parseArgs() {
 	u := getopt.StringLong("username", 'u', "beer", "Username")
 	p := getopt.StringLong("password", 'p', "beerbeer", "Password")
 	c := getopt.UintLong("civ-address", 'c', 0xa4, "CI-V address")
-	t := getopt.Uint16Long("serial-tcp-port", 't', 4533, "Expose radio's serial port on this TCP port")
+	t := getopt.Uint16Long("serial-tcp-port", 't', 4531, "Expose radio's serial port on this TCP port")
 	s := getopt.BoolLong("enable-serial-device", 's', "Expose radio's serial port as a virtual serial port")
 	r := getopt.Uint16Long("rigctld-port", 'r', 4532, "Use this TCP port for the internal rigctld")
 	e := getopt.StringLong("exec", 'e', "", "Exec cmd when connected")