diff --git a/libraries/AP_Compass/AP_Compass.cpp b/libraries/AP_Compass/AP_Compass.cpp
index 28ec2353a7..b0fcb39382 100644
--- a/libraries/AP_Compass/AP_Compass.cpp
+++ b/libraries/AP_Compass/AP_Compass.cpp
@@ -620,6 +620,13 @@ void Compass::_detect_backends(void)
         ADD_BACKEND(DRIVER_AK09916, AP_Compass_AK09916::probe(*this, hal.i2c_mgr->get_device(0, HAL_COMPASS_AK09916_I2C_ADDR),
                                                               both_i2c_external, both_i2c_external?ROTATION_YAW_270:ROTATION_NONE),
                     AP_Compass_AK09916::name, both_i2c_external);
+
+        // IST8310 on external and internal bus
+        ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(*this, hal.i2c_mgr->get_device(1, HAL_COMPASS_IST8310_I2C_ADDR),
+                                                              true, ROTATION_PITCH_180), AP_Compass_IST8310::name, true);
+
+        ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(*this, hal.i2c_mgr->get_device(0, HAL_COMPASS_IST8310_I2C_ADDR),
+                                                              both_i2c_external, ROTATION_PITCH_180), AP_Compass_IST8310::name, both_i2c_external);
 #endif // HAL_MINIMIZE_FEATURES
         }
         break;
@@ -627,7 +634,7 @@ void Compass::_detect_backends(void)
     case AP_BoardConfig::PX4_BOARD_AEROFC:
 #ifdef HAL_COMPASS_IST8310_I2C_BUS
         ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(*this, hal.i2c_mgr->get_device(HAL_COMPASS_IST8310_I2C_BUS, HAL_COMPASS_IST8310_I2C_ADDR),
-                                                              ROTATION_PITCH_180_YAW_90), AP_Compass_IST8310::name, true);
+                                                              true, ROTATION_PITCH_180_YAW_90), AP_Compass_IST8310::name, true);
 #endif
         break;
     default:
diff --git a/libraries/AP_Compass/AP_Compass_IST8310.cpp b/libraries/AP_Compass/AP_Compass_IST8310.cpp
index de9001ea53..8abb826600 100644
--- a/libraries/AP_Compass/AP_Compass_IST8310.cpp
+++ b/libraries/AP_Compass/AP_Compass_IST8310.cpp
@@ -77,13 +77,14 @@ extern const AP_HAL::HAL &hal;
 
 AP_Compass_Backend *AP_Compass_IST8310::probe(Compass &compass,
                                               AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
+                                              bool force_external,
                                               enum Rotation rotation)
 {
     if (!dev) {
         return nullptr;
     }
 
-    AP_Compass_IST8310 *sensor = new AP_Compass_IST8310(compass, std::move(dev), rotation);
+    AP_Compass_IST8310 *sensor = new AP_Compass_IST8310(compass, std::move(dev), force_external, rotation);
     if (!sensor || !sensor->init()) {
         delete sensor;
         return nullptr;
@@ -94,10 +95,12 @@ AP_Compass_Backend *AP_Compass_IST8310::probe(Compass &compass,
 
 AP_Compass_IST8310::AP_Compass_IST8310(Compass &compass,
                                        AP_HAL::OwnPtr<AP_HAL::Device> dev,
+                                       bool force_external,
                                        enum Rotation rotation)
     : AP_Compass_Backend(compass)
     , _dev(std::move(dev))
     , _rotation(rotation)
+    , _force_external(force_external)
 {
 }
 
@@ -163,6 +166,10 @@ bool AP_Compass_IST8310::init()
     _dev->set_device_type(DEVTYPE_IST8310);
     set_dev_id(_instance, _dev->get_bus_id());
 
+    if (_force_external) {
+        set_external(_instance, true);
+    }
+    
     _periodic_handle = _dev->register_periodic_callback(SAMPLING_PERIOD_USEC,
         FUNCTOR_BIND_MEMBER(&AP_Compass_IST8310::timer, void));
 
diff --git a/libraries/AP_Compass/AP_Compass_IST8310.h b/libraries/AP_Compass/AP_Compass_IST8310.h
index c6f1c88377..a466a1be5c 100644
--- a/libraries/AP_Compass/AP_Compass_IST8310.h
+++ b/libraries/AP_Compass/AP_Compass_IST8310.h
@@ -24,11 +24,16 @@
 #include "AP_Compass.h"
 #include "AP_Compass_Backend.h"
 
+#ifndef HAL_COMPASS_IST8310_I2C_ADDR
+#define HAL_COMPASS_IST8310_I2C_ADDR 0x0E
+#endif
+
 class AP_Compass_IST8310 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(Compass &compass,
                                      AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
+                                     bool force_external = false,
                                      enum Rotation rotation = ROTATION_NONE);
 
     void read() override;
@@ -38,6 +43,7 @@ public:
 private:
     AP_Compass_IST8310(Compass &compass,
                        AP_HAL::OwnPtr<AP_HAL::Device> dev,
+                       bool force_external,
                        enum Rotation rotation);
 
     void timer();
@@ -55,4 +61,5 @@ private:
     enum Rotation _rotation;
     uint8_t _instance;
     bool _ignore_next_sample;
+    bool _force_external;
 };