diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index 2f821bf587..45df59bbd3 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -132,6 +132,9 @@ const AP_Param::GroupInfo SITL::var_info2[] = {
     // @Path: ./SIM_Gripper_EPM.cpp
     AP_SUBGROUPINFO(gripper_epm_sim, "GRPE_", 24, SITL, Gripper_EPM),
 
+    // weight on wheels pin
+    AP_GROUPINFO("WOW_PIN",     25, SITL,  wow_pin, -1),
+
     AP_GROUPEND
 };
     
diff --git a/libraries/SITL/SITL.h b/libraries/SITL/SITL.h
index 60fc7a39b8..1f0a678057 100644
--- a/libraries/SITL/SITL.h
+++ b/libraries/SITL/SITL.h
@@ -197,6 +197,9 @@ public:
     // differential pressure sensor tube order
     AP_Int8 arspd_signflip;
 
+    // weight on wheels pin
+    AP_Int8 wow_pin;
+    
     uint16_t irlock_port;
 
     void simstate_send(mavlink_channel_t chan);