diff --git a/src/device/input/parse/v01.go b/src/device/input/parse/v01.go
index b9641cb..529162c 100644
--- a/src/device/input/parse/v01.go
+++ b/src/device/input/parse/v01.go
@@ -11,6 +11,7 @@ import (
 	"mayhem-party/src/device/input/wrap"
 	"net/http"
 	"os"
+	"sync"
 	"syscall"
 	"time"
 
@@ -69,9 +70,17 @@ func (v01 *V01) listen() {
 	if v01.cfg.Feedback.Addr == "" {
 		return
 	}
+	mutex := &sync.RWMutex{}
 	s := &http.Server{
 		Addr: v01.cfg.Feedback.Addr,
 		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.Method == http.MethodGet {
+				mutex.RLock()
+				defer mutex.RUnlock()
+			} else {
+				mutex.Lock()
+				defer mutex.Unlock()
+			}
 			if r.Method == http.MethodGet {
 				r = r.WithContext(v01.ctx)
 				user, ok := v01.cfg.Users[r.URL.Query().Get("user")]