diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index 4d4480e43f..37504d8897 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -1460,7 +1460,7 @@ bool AP_InertialSensor::get_accel_health_all(void) const
     return (get_accel_count() > 0);
 }
 
-#if HAL_GCS_ENABLED
+#if HAL_GCS_ENABLED && AP_AHRS_ENABLED
 /*
   calculate the trim_roll and trim_pitch. This is used for redoing the
   trim without needing a full accel cal
@@ -1521,6 +1521,7 @@ MAV_RESULT AP_InertialSensor::calibrate_trim()
 
     // reset ahrs's trim to suggested values from calibration routine
     ahrs.set_trim(trim_rad);
+
     last_accel_cal_ms = AP_HAL::millis();
     _trimming_accel = false;
     return MAV_RESULT_ACCEPTED;
@@ -1530,7 +1531,7 @@ failed:
     _trimming_accel = false;
     return MAV_RESULT_FAILED;
 }
-#endif  // HAL_GCS_ENABLED
+#endif  // HAL_GCS_ENABLED && AP_AHRS_ENABLED
 
 /*
   check if the accelerometers are calibrated in 3D and that current number of accels matched number when calibrated
@@ -2408,7 +2409,9 @@ bool AP_InertialSensor::calibrate_gyros()
     if (!gyro_calibrated_ok_all()) {
         return false;
     }
+#if AP_AHRS_ENABLED
     AP::ahrs().reset_gyro_drift();
+#endif
     return true;
 }
 
@@ -2550,8 +2553,10 @@ MAV_RESULT AP_InertialSensor::simple_accel_cal()
 #endif
         }
 
+#if AP_AHRS_ENABLED
         // force trim to zero
         AP::ahrs().set_trim(Vector3f(0, 0, 0));
+#endif
     } else {
         DEV_PRINTF("\nFAILED\n");
         // restore old values
@@ -2572,8 +2577,10 @@ MAV_RESULT AP_InertialSensor::simple_accel_cal()
         update();
     }
 
+#if AP_AHRS_ENABLED
     // and reset state estimators
     AP::ahrs().reset();
+#endif
 
     // stop flashing leds
     AP_Notify::flags.initialising = false;
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
index 9ceb54c12d..3c45c611b1 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
@@ -218,7 +218,7 @@ void AP_InertialSensor_Backend::apply_gyro_filters(const uint8_t instance, const
             continue;
         }
         bool inactive = notch.is_inactive();
-#ifndef HAL_BUILD_AP_PERIPH
+#if AP_AHRS_ENABLED
         // by default we only run the expensive notch filters on the
         // currently active IMU we reset the inactive notch filters so
         // that if we switch IMUs we're not left with old data
@@ -442,8 +442,14 @@ void AP_InertialSensor_Backend::log_gyro_raw(uint8_t instance, const uint64_t sa
         return;
     }
 
+#if AP_AHRS_ENABLED
+    const bool log_because_primary_gyro = _imu.raw_logging_option_set(AP_InertialSensor::RAW_LOGGING_OPTION::PRIMARY_GYRO_ONLY) && (instance == AP::ahrs().get_primary_gyro_index());
+#else
+    const bool log_because_primary_gyro = false;
+#endif
+
     if (_imu.raw_logging_option_set(AP_InertialSensor::RAW_LOGGING_OPTION::ALL_GYROS) ||
-        (_imu.raw_logging_option_set(AP_InertialSensor::RAW_LOGGING_OPTION::PRIMARY_GYRO_ONLY) && (instance == AP::ahrs().get_primary_gyro_index())) ||
+        log_because_primary_gyro ||
         should_log_imu_raw()) {
 
         if (_imu.raw_logging_option_set(AP_InertialSensor::RAW_LOGGING_OPTION::PRE_AND_POST_FILTER)) {