diff --git a/libraries/AP_Compass/AP_Compass_AK09916.h b/libraries/AP_Compass/AP_Compass_AK09916.h
index 01d67d2f30..8a5a10ba13 100644
--- a/libraries/AP_Compass/AP_Compass_AK09916.h
+++ b/libraries/AP_Compass/AP_Compass_AK09916.h
@@ -42,17 +42,17 @@ public:
     /* Probe for AK09916 standalone on I2C bus */
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
                                      bool force_external,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     enum Rotation rotation);
 
     /* Probe for AK09916 on auxiliary bus of ICM20948, connected through I2C */
     static AP_Compass_Backend *probe_ICM20948(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
                                              AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev_icm,
                                              bool force_external,
-                                             enum Rotation rotation = ROTATION_NONE);
+                                             enum Rotation rotation);
 
     /* Probe for AK09916 on auxiliary bus of ICM20948, connected through SPI */
     static AP_Compass_Backend *probe_ICM20948(uint8_t mpu9250_instance,
-                                             enum Rotation rotation = ROTATION_NONE);
+                                             enum Rotation rotation);
 
     static constexpr const char *name = "AK09916";
 
@@ -62,7 +62,7 @@ public:
 
 private:
     AP_Compass_AK09916(AP_AK09916_BusDriver *bus, bool force_external,
-                      enum Rotation rotation = ROTATION_NONE);
+                       enum Rotation rotation);
 
     bool init();
     void _make_factory_sensitivity_adjustment(Vector3f &field) const;
diff --git a/libraries/AP_Compass/AP_Compass_AK8963.h b/libraries/AP_Compass/AP_Compass_AK8963.h
index 377e906a95..f754da8d81 100644
--- a/libraries/AP_Compass/AP_Compass_AK8963.h
+++ b/libraries/AP_Compass/AP_Compass_AK8963.h
@@ -19,15 +19,15 @@ class AP_Compass_AK8963 : public AP_Compass_Backend
 public:
     /* Probe for AK8963 standalone on I2C bus */
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     enum Rotation rotation);
 
     /* Probe for AK8963 on auxiliary bus of MPU9250, connected through I2C */
     static AP_Compass_Backend *probe_mpu9250(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
-                                             enum Rotation rotation = ROTATION_NONE);
+                                             enum Rotation rotation);
 
     /* Probe for AK8963 on auxiliary bus of MPU9250, connected through SPI */
     static AP_Compass_Backend *probe_mpu9250(uint8_t mpu9250_instance,
-                                             enum Rotation rotation = ROTATION_NONE);
+                                             enum Rotation rotation);
 
     static constexpr const char *name = "AK8963";
 
@@ -37,7 +37,7 @@ public:
 
 private:
     AP_Compass_AK8963(AP_AK8963_BusDriver *bus,
-                      enum Rotation rotation = ROTATION_NONE);
+                      enum Rotation rotation);
 
     bool init();
     void _make_factory_sensitivity_adjustment(Vector3f &field) const;
diff --git a/libraries/AP_Compass/AP_Compass_HMC5843.h b/libraries/AP_Compass/AP_Compass_HMC5843.h
index 90c01cfd58..654172d301 100644
--- a/libraries/AP_Compass/AP_Compass_HMC5843.h
+++ b/libraries/AP_Compass/AP_Compass_HMC5843.h
@@ -17,10 +17,10 @@ class AP_Compass_HMC5843 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::Device> dev,
-                                     bool force_external = false,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     bool force_external,
+                                     enum Rotation rotation);
 
-    static AP_Compass_Backend *probe_mpu6000(enum Rotation rotation = ROTATION_NONE);
+    static AP_Compass_Backend *probe_mpu6000(enum Rotation rotation);
 
     static constexpr const char *name = "HMC5843";
 
diff --git a/libraries/AP_Compass/AP_Compass_IST8308.h b/libraries/AP_Compass/AP_Compass_IST8308.h
index 8680eab25f..dd1c595065 100644
--- a/libraries/AP_Compass/AP_Compass_IST8308.h
+++ b/libraries/AP_Compass/AP_Compass_IST8308.h
@@ -32,8 +32,8 @@ class AP_Compass_IST8308 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
-                                     bool force_external = false,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     bool force_external,
+                                     enum Rotation rotation);
 
     void read() override;
 
diff --git a/libraries/AP_Compass/AP_Compass_IST8310.h b/libraries/AP_Compass/AP_Compass_IST8310.h
index 485ddbbb0b..65073f21b4 100644
--- a/libraries/AP_Compass/AP_Compass_IST8310.h
+++ b/libraries/AP_Compass/AP_Compass_IST8310.h
@@ -32,8 +32,8 @@ class AP_Compass_IST8310 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
-                                     bool force_external = false,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     bool force_external,
+                                     enum Rotation rotation);
 
     void read() override;
 
diff --git a/libraries/AP_Compass/AP_Compass_LIS3MDL.h b/libraries/AP_Compass/AP_Compass_LIS3MDL.h
index 51406d154b..bc18660c61 100644
--- a/libraries/AP_Compass/AP_Compass_LIS3MDL.h
+++ b/libraries/AP_Compass/AP_Compass_LIS3MDL.h
@@ -34,8 +34,8 @@ class AP_Compass_LIS3MDL : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::Device> dev,
-                                     bool force_external = false,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     bool force_external,
+                                     enum Rotation rotation);
 
     void read() override;
 
diff --git a/libraries/AP_Compass/AP_Compass_LSM303D.h b/libraries/AP_Compass/AP_Compass_LSM303D.h
index 0a3fd62668..7c72d41ede 100644
--- a/libraries/AP_Compass/AP_Compass_LSM303D.h
+++ b/libraries/AP_Compass/AP_Compass_LSM303D.h
@@ -12,7 +12,7 @@ class AP_Compass_LSM303D : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::Device> dev,
-                                     enum Rotation = ROTATION_NONE);
+                                     enum Rotation rotation);
 
     static constexpr const char *name = "LSM303D";
 
diff --git a/libraries/AP_Compass/AP_Compass_LSM9DS1.h b/libraries/AP_Compass/AP_Compass_LSM9DS1.h
index 611051c3cd..587c598a0c 100644
--- a/libraries/AP_Compass/AP_Compass_LSM9DS1.h
+++ b/libraries/AP_Compass/AP_Compass_LSM9DS1.h
@@ -12,7 +12,7 @@ class AP_Compass_LSM9DS1 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::Device> dev,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     enum Rotation rotation);
 
     static constexpr const char *name = "LSM9DS1";
 
@@ -22,7 +22,7 @@ public:
 
 private:
     AP_Compass_LSM9DS1(AP_HAL::OwnPtr<AP_HAL::Device> dev,
-                       enum Rotation rotation = ROTATION_NONE);
+                       enum Rotation rotation);
     bool init();
     bool _check_id(void);
     bool _configure(void);
diff --git a/libraries/AP_Compass/AP_Compass_MAG3110.h b/libraries/AP_Compass/AP_Compass_MAG3110.h
index b1a5feeaa7..41b27b12e1 100644
--- a/libraries/AP_Compass/AP_Compass_MAG3110.h
+++ b/libraries/AP_Compass/AP_Compass_MAG3110.h
@@ -17,7 +17,7 @@ class AP_Compass_MAG3110 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::Device> dev,
-                                     enum Rotation = ROTATION_NONE);
+                                     enum Rotation rotation);
 
     static constexpr const char *name = "MAG3110";
 
diff --git a/libraries/AP_Compass/AP_Compass_MMC3416.h b/libraries/AP_Compass/AP_Compass_MMC3416.h
index 4dc95cf189..f2a9c8c3ee 100644
--- a/libraries/AP_Compass/AP_Compass_MMC3416.h
+++ b/libraries/AP_Compass/AP_Compass_MMC3416.h
@@ -30,8 +30,8 @@ class AP_Compass_MMC3416 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
-                                     bool force_external = false,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     bool force_external,
+                                     enum Rotation rotation);
 
     void read() override;
 
diff --git a/libraries/AP_Compass/AP_Compass_QMC5883L.h b/libraries/AP_Compass/AP_Compass_QMC5883L.h
index 3940bc71fc..bbf601585f 100644
--- a/libraries/AP_Compass/AP_Compass_QMC5883L.h
+++ b/libraries/AP_Compass/AP_Compass_QMC5883L.h
@@ -44,7 +44,7 @@ class AP_Compass_QMC5883L : public AP_Compass_Backend
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
 									 bool force_external,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     enum Rotation rotation);
 
     void read() override;
 
diff --git a/libraries/AP_Compass/AP_Compass_RM3100.h b/libraries/AP_Compass/AP_Compass_RM3100.h
index 50d38a55f3..d97a6ddbf3 100644
--- a/libraries/AP_Compass/AP_Compass_RM3100.h
+++ b/libraries/AP_Compass/AP_Compass_RM3100.h
@@ -30,8 +30,8 @@ class AP_Compass_RM3100 : public AP_Compass_Backend
 {
 public:
     static AP_Compass_Backend *probe(AP_HAL::OwnPtr<AP_HAL::Device> dev,
-                                     bool force_external = false,
-                                     enum Rotation rotation = ROTATION_NONE);
+                                     bool force_external,
+                                     enum Rotation rotation);
 
     void read() override;