diff --git a/sonoff/language/ru-RU.h b/sonoff/language/ru-RU.h
index 28aa1d7f2..42da36d05 100644
--- a/sonoff/language/ru-RU.h
+++ b/sonoff/language/ru-RU.h
@@ -110,6 +110,7 @@
 #define D_IP_ADDRESS "IP Адрес"
 #define D_LIGHT "Свет"
 #define D_LWT "LWT"
+#define D_MMHG "мм рт.ст."
 #define D_MODULE "Модуль"
 #define D_MQTT "MQTT"
 #define D_MULTI_PRESS "многократное нажатие"