diff --git a/sonoff/sonoff.h b/sonoff/sonoff.h
index 357409813..5dd01a632 100644
--- a/sonoff/sonoff.h
+++ b/sonoff/sonoff.h
@@ -137,7 +137,7 @@ typedef unsigned long power_t;              // Power (Relay) type
 #define DAWN_NAUTIC            -12.0
 #define DAWN_ASTRONOMIC        -18.0
 
-// Sensor definition for KNX Driver
+// Sensor and Commands definition for KNX Driver
 #define KNX_TEMPERATURE        17
 #define KNX_HUMIDITY           18
 #define KNX_ENERGY_VOLTAGE     19
@@ -153,6 +153,7 @@ typedef unsigned long power_t;              // Power (Relay) type
 #define KNX_SLOT4              29
 #define KNX_SLOT5              30
 #define KNX_MAX_device_param   30
+#define MAX_KNXTX_CMNDS        5
 
 /*********************************************************************************************\
  * Enumeration