diff --git a/sonoff/language/bg-BG.h b/sonoff/language/bg-BG.h
index d774276e8..94d87c958 100644
--- a/sonoff/language/bg-BG.h
+++ b/sonoff/language/bg-BG.h
@@ -110,6 +110,7 @@
 #define D_IP_ADDRESS "IP адрес"
 #define D_LIGHT "Светлина"
 #define D_LWT "LWT"
+#define D_MMHG "mmHg"
 #define D_MODULE "Модул"
 #define D_MQTT "MQTT"
 #define D_MULTI_PRESS "множествено натискане"