diff --git a/conf.go b/conf.go
index 7b1be58..791e101 100644
--- a/conf.go
+++ b/conf.go
@@ -133,8 +133,3 @@ func parseConf(filename string) *Conf {
 
 	return &conf
 }
-
-func parseArgs() map[string]string {
-	var args map[string]string
-	return args
-}
diff --git a/main.go b/main.go
index 1758f29..7314dd0 100644
--- a/main.go
+++ b/main.go
@@ -2,8 +2,10 @@ package main
 
 import (
 	"bufio"
+	"flag"
 	"fmt"
 	"log"
+	"os"
 	"os/exec"
 	"strings"
 	"time"
@@ -89,7 +91,15 @@ func (s *Stream) handle() {
 }
 
 func main() {
-	conf := parseConf("./reaction.yml")
+	confFilename := flag.String("c", "", "configuration file. see an example at https://framagit.org/ppom/reaction/-/blob/main/reaction.yml")
+	flag.Parse()
+
+	if *confFilename == "" {
+		flag.PrintDefaults()
+		os.Exit(2)
+	}
+
+	conf := parseConf(*confFilename)
 
 	for _, stream := range conf.Streams {
 		go stream.handle()