diff --git a/sonoff/language/fr-FR.h b/sonoff/language/fr-FR.h
index 0e37d9990..8461dfa04 100644
--- a/sonoff/language/fr-FR.h
+++ b/sonoff/language/fr-FR.h
@@ -110,6 +110,7 @@
 #define D_IP_ADDRESS "Adresse IP"
 #define D_LIGHT "Lumière"
 #define D_LWT "LWT"
+#define D_MMHG "mmHg"
 #define D_MODULE "Module"
 #define D_MQTT "MQTT"
 #define D_MULTI_PRESS "multi-pression"