diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
index 3c45c611b1..85c9ed8f34 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
@@ -1,6 +1,7 @@
 #define AP_INLINE_VECTOR_OPS
 
 #include <AP_HAL/AP_HAL.h>
+#include <AP_AHRS/AP_AHRS.h>
 #include "AP_InertialSensor.h"
 #include "AP_InertialSensor_Backend.h"
 #include <AP_Logger/AP_Logger.h>
@@ -816,6 +817,7 @@ void AP_InertialSensor_Backend::update_accel(uint8_t instance) /* front end */
     }
 }
 
+#if HAL_LOGGING_ENABLED
 bool AP_InertialSensor_Backend::should_log_imu_raw() const
 {
     if (_imu._log_raw_bit == (uint32_t)-1) {
@@ -831,6 +833,7 @@ bool AP_InertialSensor_Backend::should_log_imu_raw() const
     }
     return true;
 }
+#endif  // HAL_LOGGING_ENABLED
 
 // log an unexpected change in a register for an IMU
 void AP_InertialSensor_Backend::log_register_change(uint32_t bus_id, const AP_HAL::Device::checkreg &reg)
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h
index 880571ee4f..e51d9362b8 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h
@@ -312,7 +312,7 @@ protected:
     */
     void notify_accel_fifo_reset(uint8_t instance) __RAMFUNC__;
     void notify_gyro_fifo_reset(uint8_t instance) __RAMFUNC__;
-    
+
     // log an unexpected change in a register for an IMU
     void log_register_change(uint32_t bus_id, const AP_HAL::Device::checkreg &reg) __RAMFUNC__;
 
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Logging.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Logging.cpp
index e59019d7de..2318766a67 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Logging.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Logging.cpp
@@ -1,3 +1,7 @@
+#include <AP_Logger/AP_Logger_config.h>
+
+#if HAL_LOGGING_ENABLED
+
 #include "AP_InertialSensor.h"
 #include "AP_InertialSensor_Backend.h"
 
@@ -188,3 +192,5 @@ void AP_InertialSensor::write_notch_log_messages() const
         }
     }
 }
+
+#endif  // HAL_LOGGING_ENABLED
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_tempcal.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_tempcal.cpp
index 486d14965a..ef5062cb93 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_tempcal.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_tempcal.cpp
@@ -26,6 +26,7 @@
 #include <AP_Logger/AP_Logger.h>
 #include <AP_Common/ExpandingString.h>
 #include <AP_Notify/AP_Notify.h>
+#include "AP_InertialSensor.h"
 
 // this scale factor ensures params are easy to work with in GUI parameter editors
 #define SCALE_FACTOR 1.0e6