diff --git a/libraries/AP_Compass/AP_Compass.cpp b/libraries/AP_Compass/AP_Compass.cpp
index c6c3e58877..f468578deb 100644
--- a/libraries/AP_Compass/AP_Compass.cpp
+++ b/libraries/AP_Compass/AP_Compass.cpp
@@ -1677,7 +1677,7 @@ const Vector3f& Compass::getHIL(uint8_t instance) const
 void Compass::_setup_earth_field(void)
 {
     // assume a earth field strength of 400
-    _hil.Bearth(400, 0, 0);
+    _hil.Bearth = {400, 0, 0};
 
     // rotate _Bearth for inclination and declination. -66 degrees
     // is the inclination in Canberra, Australia
diff --git a/libraries/AP_Compass/AP_Compass_LIS3MDL.cpp b/libraries/AP_Compass/AP_Compass_LIS3MDL.cpp
index f65a07e218..0afa3d3a8c 100644
--- a/libraries/AP_Compass/AP_Compass_LIS3MDL.cpp
+++ b/libraries/AP_Compass/AP_Compass_LIS3MDL.cpp
@@ -138,7 +138,6 @@ void AP_Compass_LIS3MDL::timer()
         int16_t magz;
     } data;
     const float range_scale = 1000.0f / 6842.0f;
-    Vector3f field;
 
     // check data ready
     uint8_t status;
@@ -154,9 +153,15 @@ void AP_Compass_LIS3MDL::timer()
         goto check_registers;
     }
 
-    field(data.magx * range_scale, data.magy * range_scale, data.magz * range_scale);
+    {
+        Vector3f field{
+            data.magx * range_scale,
+            data.magy * range_scale,
+            data.magz * range_scale,
+        };
 
-    accumulate_sample(field, compass_instance);
+        accumulate_sample(field, compass_instance);
+    }
 
 check_registers:
     dev->check_next_register();
diff --git a/libraries/AP_Compass/AP_Compass_RM3100.cpp b/libraries/AP_Compass/AP_Compass_RM3100.cpp
index 3b69a7c19c..2b7b6f206c 100644
--- a/libraries/AP_Compass/AP_Compass_RM3100.cpp
+++ b/libraries/AP_Compass/AP_Compass_RM3100.cpp
@@ -177,7 +177,6 @@ void AP_Compass_RM3100::timer()
         uint8_t magz_1;
         uint8_t magz_0;
     } data;
-    Vector3f field;
 
     int32_t magx = 0;
     int32_t magy = 0;
@@ -209,10 +208,16 @@ void AP_Compass_RM3100::timer()
     magy >>= 8;
     magz >>= 8;
 
-    // apply scaler and store in field vector
-    field(magx * _scaler, magy * _scaler, magz * _scaler);
+    {
+        // apply scaler and store in field vector
+         Vector3f field{
+             magx * _scaler,
+             magy * _scaler,
+             magz * _scaler
+         };
 
-    accumulate_sample(field, compass_instance);
+        accumulate_sample(field, compass_instance);
+    }
 
 check_registers:
     dev->check_next_register();
diff --git a/libraries/AP_Compass/AP_Compass_SITL.cpp b/libraries/AP_Compass/AP_Compass_SITL.cpp
index c9f7f6c975..244c89148e 100644
--- a/libraries/AP_Compass/AP_Compass_SITL.cpp
+++ b/libraries/AP_Compass/AP_Compass_SITL.cpp
@@ -51,7 +51,7 @@ void AP_Compass_SITL::_setup_eliptical_correcion(uint8_t i)
 {
     Vector3f diag = _sitl->mag_diag[i].get();
     if (diag.is_zero()) {
-        diag(1,1,1);
+        diag = {1,1,1};
     }
     const Vector3f &diagonals = diag;
     const Vector3f &offdiagonals = _sitl->mag_offdiag[i];