diff --git a/main.go b/main.go
index 8bdebd1a..7f35b4c1 100644
--- a/main.go
+++ b/main.go
@@ -63,24 +63,40 @@ type program struct {
 	udplRtcp  *serverUdpListener
 }
 
-func newProgram(args args) (*program, error) {
-	if args.protocolsStr == "" {
-		args.protocolsStr = "udp,tcp"
-	}
-	if args.rtspPort == 0 {
-		args.rtspPort = 8554
-	}
-	if args.rtpPort == 0 {
-		args.rtpPort = 8000
-	}
-	if args.rtcpPort == 0 {
-		args.rtcpPort = 8001
-	}
-	if args.readTimeout == time.Duration(0) {
-		args.readTimeout = 5 * time.Second
-	}
-	if args.writeTimeout == time.Duration(0) {
-		args.writeTimeout = 5 * time.Second
+func newProgram(sargs []string) (*program, error) {
+	kingpin.CommandLine.Help = "rtsp-simple-server " + Version + "\n\n" +
+		"RTSP server."
+
+	argVersion := kingpin.Flag("version", "print rtsp-simple-server version").Bool()
+	argProtocolsStr := kingpin.Flag("protocols", "supported protocols").Default("udp,tcp").String()
+	argRtspPort := kingpin.Flag("rtsp-port", "port of the RTSP TCP listener").Default("8554").Int()
+	argRtpPort := kingpin.Flag("rtp-port", "port of the RTP UDP listener").Default("8000").Int()
+	argRtcpPort := kingpin.Flag("rtcp-port", "port of the RTCP UDP listener").Default("8001").Int()
+	argReadTimeout := kingpin.Flag("read-timeout", "timeout for read operations").Default("5s").Duration()
+	argWriteTimeout := kingpin.Flag("write-timeout", "timeout for write operations").Default("5s").Duration()
+	argPublishUser := kingpin.Flag("publish-user", "optional username required to publish").Default("").String()
+	argPublishPass := kingpin.Flag("publish-pass", "optional password required to publish").Default("").String()
+	argReadUser := kingpin.Flag("read-user", "optional username required to read").Default("").String()
+	argReadPass := kingpin.Flag("read-pass", "optional password required to read").Default("").String()
+	argPreScript := kingpin.Flag("pre-script", "optional script to run on client connect").Default("").String()
+	argPostScript := kingpin.Flag("post-script", "optional script to run on client disconnect").Default("").String()
+
+	kingpin.MustParse(kingpin.CommandLine.Parse(sargs))
+
+	args := args{
+		version:      *argVersion,
+		protocolsStr: *argProtocolsStr,
+		rtspPort:     *argRtspPort,
+		rtpPort:      *argRtpPort,
+		rtcpPort:     *argRtcpPort,
+		readTimeout:  *argReadTimeout,
+		writeTimeout: *argWriteTimeout,
+		publishUser:  *argPublishUser,
+		publishPass:  *argPublishPass,
+		readUser:     *argReadUser,
+		readPass:     *argReadPass,
+		preScript:    *argPreScript,
+		postScript:   *argPostScript,
 	}
 
 	if args.version == true {
@@ -88,14 +104,6 @@ func newProgram(args args) (*program, error) {
 		os.Exit(0)
 	}
 
-	if (args.rtpPort % 2) != 0 {
-		return nil, fmt.Errorf("rtp port must be even")
-	}
-
-	if args.rtcpPort != (args.rtpPort + 1) {
-		return nil, fmt.Errorf("rtcp and rtp ports must be consecutive")
-	}
-
 	protocols := make(map[streamProtocol]struct{})
 	for _, proto := range strings.Split(args.protocolsStr, ",") {
 		switch proto {
@@ -112,21 +120,37 @@ func newProgram(args args) (*program, error) {
 	if len(protocols) == 0 {
 		return nil, fmt.Errorf("no protocols provided")
 	}
-
+	if (args.rtpPort % 2) != 0 {
+		return nil, fmt.Errorf("rtp port must be even")
+	}
+	if args.rtcpPort != (args.rtpPort + 1) {
+		return nil, fmt.Errorf("rtcp and rtp ports must be consecutive")
+	}
 	if args.publishUser != "" {
 		if !regexp.MustCompile("^[a-zA-Z0-9]+$").MatchString(args.publishUser) {
 			return nil, fmt.Errorf("publish username must be alphanumeric")
 		}
 	}
-
 	if args.publishPass != "" {
 		if !regexp.MustCompile("^[a-zA-Z0-9]+$").MatchString(args.publishPass) {
 			return nil, fmt.Errorf("publish password must be alphanumeric")
 		}
 	}
-
-	if args.publishUser != "" && args.publishPass == "" || args.publishUser == "" && args.publishPass != "" {
-		return nil, fmt.Errorf("publish username and password must be both filled")
+	if args.readUser != "" && args.readPass == "" || args.readUser == "" && args.readPass != "" {
+		return nil, fmt.Errorf("read username and password must be both filled")
+	}
+	if args.readUser != "" {
+		if !regexp.MustCompile("^[a-zA-Z0-9]+$").MatchString(args.readUser) {
+			return nil, fmt.Errorf("read username must be alphanumeric")
+		}
+	}
+	if args.readPass != "" {
+		if !regexp.MustCompile("^[a-zA-Z0-9]+$").MatchString(args.readPass) {
+			return nil, fmt.Errorf("read password must be alphanumeric")
+		}
+	}
+	if args.readUser != "" && args.readPass == "" || args.readUser == "" && args.readPass != "" {
+		return nil, fmt.Errorf("read username and password must be both filled")
 	}
 
 	log.Printf("rtsp-simple-server %s", Version)
@@ -167,40 +191,7 @@ func (p *program) close() {
 }
 
 func main() {
-	kingpin.CommandLine.Help = "rtsp-simple-server " + Version + "\n\n" +
-		"RTSP server."
-
-	argVersion := kingpin.Flag("version", "print rtsp-simple-server version").Bool()
-	argProtocolsStr := kingpin.Flag("protocols", "supported protocols").Default("udp,tcp").String()
-	argRtspPort := kingpin.Flag("rtsp-port", "port of the RTSP TCP listener").Default("8554").Int()
-	argRtpPort := kingpin.Flag("rtp-port", "port of the RTP UDP listener").Default("8000").Int()
-	argRtcpPort := kingpin.Flag("rtcp-port", "port of the RTCP UDP listener").Default("8001").Int()
-	argReadTimeout := kingpin.Flag("read-timeout", "timeout for read operations").Default("5s").Duration()
-	argWriteTimeout := kingpin.Flag("write-timeout", "timeout for write operations").Default("5s").Duration()
-	argPublishUser := kingpin.Flag("publish-user", "optional username required to publish").Default("").String()
-	argPublishPass := kingpin.Flag("publish-pass", "optional password required to publish").Default("").String()
-	argReadUser := kingpin.Flag("read-user", "optional username required to read").Default("").String()
-	argReadPass := kingpin.Flag("read-pass", "optional password required to read").Default("").String()
-	argPreScript := kingpin.Flag("pre-script", "optional script to run on client connect").Default("").String()
-	argPostScript := kingpin.Flag("post-script", "optional script to run on client disconnect").Default("").String()
-
-	kingpin.Parse()
-
-	_, err := newProgram(args{
-		version:      *argVersion,
-		protocolsStr: *argProtocolsStr,
-		rtspPort:     *argRtspPort,
-		rtpPort:      *argRtpPort,
-		rtcpPort:     *argRtcpPort,
-		readTimeout:  *argReadTimeout,
-		writeTimeout: *argWriteTimeout,
-		publishUser:  *argPublishUser,
-		publishPass:  *argPublishPass,
-		readUser:     *argReadUser,
-		readPass:     *argReadPass,
-		preScript:    *argPreScript,
-		postScript:   *argPostScript,
-	})
+	_, err := newProgram(os.Args[1:])
 	if err != nil {
 		log.Fatal("ERR: ", err)
 	}
diff --git a/main_test.go b/main_test.go
index f2af2bf9..dc6d031a 100644
--- a/main_test.go
+++ b/main_test.go
@@ -61,7 +61,7 @@ func TestProtocols(t *testing.T) {
 		{"tcp", "tcp"},
 	} {
 		t.Run(pair[0]+"_"+pair[1], func(t *testing.T) {
-			p, err := newProgram(args{})
+			p, err := newProgram([]string{})
 			require.NoError(t, err)
 			defer p.close()
 
@@ -103,9 +103,9 @@ func TestProtocols(t *testing.T) {
 }
 
 func TestPublishAuth(t *testing.T) {
-	p, err := newProgram(args{
-		publishUser: "testuser",
-		publishPass: "testpass",
+	p, err := newProgram([]string{
+		"--publish-user=testuser",
+		"--publish-pass=testpass",
 	})
 	require.NoError(t, err)
 	defer p.close()
@@ -146,9 +146,9 @@ func TestPublishAuth(t *testing.T) {
 }
 
 func TestReadAuth(t *testing.T) {
-	p, err := newProgram(args{
-		readUser: "testuser",
-		readPass: "testpass",
+	p, err := newProgram([]string{
+		"--read-user=testuser",
+		"--read-pass=testpass",
 	})
 	require.NoError(t, err)
 	defer p.close()