diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
index a5a0ee4da5..1ac658cb14 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
@@ -609,7 +609,7 @@ bool AP_InertialSensor_Backend::should_log_imu_raw() const
 // 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)
 {
-    AP::logger().Write("IREG", "TimeUS,DevID,Bank,Reg,Val", "QUBBB",
+    AP::logger().Write("IREG", "TimeUS,DevID,Bank,Reg,Val", "QIBBB",
                        AP_HAL::micros64(),
                        bus_id,
                        reg.bank,