diff --git a/tools/esp8266/README.md b/tools/esp8266/README.md
index 8ea1ade0..7aaec24b 100644
--- a/tools/esp8266/README.md
+++ b/tools/esp8266/README.md
@@ -51,6 +51,7 @@ The serial console will print the converted values which were read out of the in
 
 For now the following inverters should work out of the box:
 
+- HM300
 - HM350
 - HM400
 - HM600
@@ -68,4 +69,4 @@ For now the following inverters should work out of the box:
 - `Time` 1.6.1
 - `RF24` 1.4.5
 - `PubSubClient` 2.8
-- `ArduinoJson` 6.19.4
\ No newline at end of file
+- `ArduinoJson` 6.19.4