diff --git a/esp8266/webinterface.cpp b/esp8266/webinterface.cpp
index a862df11..c3487e58 100644
--- a/esp8266/webinterface.cpp
+++ b/esp8266/webinterface.cpp
@@ -24,6 +24,7 @@
 #include "wifi.h"
 #include <WiFiClient.h>
 #include <WiFiServer.h>
+#include <WiFiUdp.h>
 #include <ESP8266WiFi.h>
 #include <ESP8266WebServer.h>
 extern "C" {