diff --git a/sonoff/language/el-GR.h b/sonoff/language/el-GR.h
index c5a3db324..86e6c5076 100644
--- a/sonoff/language/el-GR.h
+++ b/sonoff/language/el-GR.h
@@ -111,6 +111,7 @@
 #define D_IP_ADDRESS "IP Address"
 #define D_LIGHT "Light"
 #define D_LWT "LWT"
+#define D_MMHG "mmHg"
 #define D_MODULE "Module"
 #define D_MQTT "MQTT"
 #define D_MULTI_PRESS "πολλαπλή πίεση"