diff --git a/TODO b/TODO
index ebdc0cb..60ab545 100644
--- a/TODO
+++ b/TODO
@@ -12,7 +12,7 @@
 [ ] *.. Add robots.txt.
 [x] *.. Compile static files into the binary.
 [ ] *** Read route preferences from env/config.
-[ ] *.. Make the port configurable via CLI option.
+[x] *.. Make the port configurable via CLI option.
 [ ] *.. Make the stop name link to Breng's page for that stop.
 [ ] *.. Make the route name link to Breng's page for that route.
 
diff --git a/main.go b/main.go
index fa2fd7b..a53f672 100644
--- a/main.go
+++ b/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -37,6 +38,11 @@ var BusClient *http.Client
 var Quays []Quay = []Quay{}
 
 func main() {
+	var port int
+
+	flag.IntVar(&port, "p", 4444, "The port to start the server on")
+	flag.Parse()
+
 	BusClient = &http.Client{}
-	serveHttp()
+	serveHttp(port)
 }
diff --git a/server.go b/server.go
index 3157a96..7482f10 100644
--- a/server.go
+++ b/server.go
@@ -2,9 +2,11 @@ package main
 
 import (
 	"embed"
+	"fmt"
 	"html/template"
 	"log"
 	"net/http"
+	"strconv"
 	"time"
 )
 
@@ -30,13 +32,13 @@ func formatTime(t time.Time) string {
 
 var tplFunctions = template.FuncMap{"formatTime": formatTime}
 
-func serveHttp() {
+func serveHttp(port int) {
 	http.HandleFunc("/", handleIndex)
 	http.Handle("/static/", http.FileServer(http.FS(staticDir)))
 
-	log.Println("Serving on port 4444")
+	log.Printf("Listening on port %s\n", strconv.Itoa(port))
 
-	err := http.ListenAndServe(":4444", nil)
+	err := http.ListenAndServe(fmt.Sprintf(":%s", strconv.Itoa(port)), nil)
 	if err != nil {
 		log.Fatal(err)
 	}