diff --git a/esp-link/cgiwifi.h b/esp-link/cgiwifi.h
index 5fa177c..667f27d 100644
--- a/esp-link/cgiwifi.h
+++ b/esp-link/cgiwifi.h
@@ -19,6 +19,7 @@ void configWifiIP();
 void wifiInit(void);
 void wifiAddStateChangeCb(WifiStateChangeCb cb);
 void wifiStartMDNS(struct ip_addr);
+int checkString(char *str);
 
 extern uint8_t wifiState;
 extern bool mdns_started;