diff --git a/libraries/AP_InertialSensor/AuxiliaryBus.cpp b/libraries/AP_InertialSensor/AuxiliaryBus.cpp
index 4697cb3337..1335d421c3 100644
--- a/libraries/AP_InertialSensor/AuxiliaryBus.cpp
+++ b/libraries/AP_InertialSensor/AuxiliaryBus.cpp
@@ -1,5 +1,4 @@
 #include <assert.h>
-#include <errno.h>
 #include <stdlib.h>
 
 #include "AuxiliaryBus.h"