diff --git a/ArduSub/GCS_Mavlink.cpp b/ArduSub/GCS_Mavlink.cpp
index e1df00bc44..cdd03e55f8 100644
--- a/ArduSub/GCS_Mavlink.cpp
+++ b/ArduSub/GCS_Mavlink.cpp
@@ -251,14 +251,6 @@ void NOINLINE Sub::send_nav_controller_output(mavlink_channel_t chan)
         0);
 }
 
-// report simulator state
-void NOINLINE Sub::send_simstate(mavlink_channel_t chan)
-{
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-    sitl.simstate_send(chan);
-#endif
-}
-
 void NOINLINE Sub::send_vfr_hud(mavlink_channel_t chan)
 {
     mavlink_msg_vfr_hud_send(
@@ -461,15 +453,6 @@ bool GCS_MAVLINK_Sub::try_send_message(enum ap_message id)
 #endif
         break;
 
-    case MSG_SIMSTATE:
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-        CHECK_PAYLOAD_SIZE(SIMSTATE);
-        sub.send_simstate(chan);
-#endif
-        CHECK_PAYLOAD_SIZE(AHRS2);
-        send_ahrs2();
-        break;
-
     case MSG_MOUNT_STATUS:
 #if MOUNT == ENABLED
         CHECK_PAYLOAD_SIZE(MOUNT_STATUS);
diff --git a/ArduSub/Sub.h b/ArduSub/Sub.h
index 1d897a91de..a721db8cbe 100644
--- a/ArduSub/Sub.h
+++ b/ArduSub/Sub.h
@@ -476,7 +476,6 @@ private:
     void send_heartbeat(mavlink_channel_t chan);
     void send_extended_status1(mavlink_channel_t chan);
     void send_nav_controller_output(mavlink_channel_t chan);
-    void send_simstate(mavlink_channel_t chan);
     void send_vfr_hud(mavlink_channel_t chan);
 #if RPM_ENABLED == ENABLED
     void send_rpm(mavlink_channel_t chan);