diff --git a/ArduPlane/GCS_Mavlink.cpp b/ArduPlane/GCS_Mavlink.cpp
index 84c00518ce..9427b99e0c 100644
--- a/ArduPlane/GCS_Mavlink.cpp
+++ b/ArduPlane/GCS_Mavlink.cpp
@@ -649,7 +649,9 @@ static const ap_message STREAM_RC_CHANNELS_msgs[] = {
 };
 static const ap_message STREAM_EXTRA1_msgs[] = {
     MSG_ATTITUDE,
+#if AP_SIM_ENABLED
     MSG_SIMSTATE,
+#endif
     MSG_AHRS2,
 #if AP_RPM_ENABLED
     MSG_RPM,