diff --git a/tcpproxy.go b/tcpproxy.go
index 9bbc1a4..8a9bd4c 100644
--- a/tcpproxy.go
+++ b/tcpproxy.go
@@ -172,6 +172,8 @@ func (p *Proxy) AddRoute(ipPort string, dest Target) (routeID int) {
 // Both AddRoute and RemoveRoute is go-routine safe.
 func (p *Proxy) RemoveRoute(ipPort string, routeID int) {
 	cfg := p.configFor(ipPort)
+	cfg.Lock()
+	defer cfg.Unlock()
 	cfg.routes[routeID] = nil
 }
 
@@ -255,6 +257,8 @@ func (p *Proxy) serveListener(ret chan<- error, ln net.Listener, cfg *config) {
 // It returns whether it matched purely for testing.
 func (p *Proxy) serveConn(c net.Conn, cfg *config) bool {
 	br := bufio.NewReader(c)
+	cfg.Lock()
+	defer cfg.Unlock()
 	for _, route := range cfg.routes {
 		if route == nil {
 			continue