diff --git a/tools/esp8266/web.cpp b/tools/esp8266/web.cpp
index 9e4e9802..5ccdb002 100644
--- a/tools/esp8266/web.cpp
+++ b/tools/esp8266/web.cpp
@@ -185,7 +185,7 @@ void web::showSetup(void) {
inv += F("serial.u64, HEX);
- inv += F("\"/ maxlength=\"12\" onkeyup=\"checkSerial()\">");
+ inv += F("\"/ maxlength=\"12\">");
inv += F("");
inv += F("