diff --git a/sonoff/language/zh-CN.h b/sonoff/language/zh-CN.h
index f4a19e324..141cfdaff 100644
--- a/sonoff/language/zh-CN.h
+++ b/sonoff/language/zh-CN.h
@@ -110,6 +110,7 @@
 #define D_IP_ADDRESS "IP地址"
 #define D_LIGHT "灯"
 #define D_LWT "LWT"
+#define D_MMHG "mmHg"
 #define D_MODULE "模块"
 #define D_MQTT "MQTT"
 #define D_MULTI_PRESS "多次按键"