diff --git a/libraries/AP_Compass/AP_Compass_AK8963.cpp b/libraries/AP_Compass/AP_Compass_AK8963.cpp
index d78f2df616..b8401ade14 100644
--- a/libraries/AP_Compass/AP_Compass_AK8963.cpp
+++ b/libraries/AP_Compass/AP_Compass_AK8963.cpp
@@ -284,7 +284,7 @@ bool AP_Compass_AK8963_MPU9250::read_raw()
         _mag_y = (float) int16_val(rx, 2);
         _mag_z = (float) int16_val(rx, 3);
 
-        if (AP_Math::is_zero(_mag_x) && AP_Math::is_zero(_mag_y) && AP_Math::is_zero(_mag_z)) {
+        if (is_zero(_mag_x) && is_zero(_mag_y) && is_zero(_mag_z)) {
             return false;
         }
 
diff --git a/libraries/AP_Compass/AP_Compass_Backend.cpp b/libraries/AP_Compass/AP_Compass_Backend.cpp
index 17a1d072b0..638ff6d928 100644
--- a/libraries/AP_Compass/AP_Compass_Backend.cpp
+++ b/libraries/AP_Compass/AP_Compass_Backend.cpp
@@ -60,7 +60,7 @@ void AP_Compass_Backend::apply_corrections(Vector3f &mag, uint8_t i)
       being applied so it can be logged correctly
      */
     mag += offsets;
-    if(_compass._motor_comp_type != AP_COMPASS_MOT_COMP_DISABLED && !AP_Math::is_zero(_compass._thr_or_curr)) {
+    if(_compass._motor_comp_type != AP_COMPASS_MOT_COMP_DISABLED && !is_zero(_compass._thr_or_curr)) {
         state.motor_offset = mot * _compass._thr_or_curr;
         mag += state.motor_offset;
     } else {
diff --git a/libraries/AP_Compass/Compass.cpp b/libraries/AP_Compass/Compass.cpp
index c4fd0d6b57..d5a9436803 100644
--- a/libraries/AP_Compass/Compass.cpp
+++ b/libraries/AP_Compass/Compass.cpp
@@ -533,7 +533,7 @@ bool Compass::configured(uint8_t i)
     }
 
     // exit immediately if all offsets are zero
-    if (AP_Math::is_zero(get_offsets(i).length())) {
+    if (is_zero(get_offsets(i).length())) {
         return false;
     }
 
@@ -575,7 +575,7 @@ void Compass::setHIL(float roll, float pitch, float yaw)
     // create a rotation matrix for the given attitude
     R.from_euler(roll, pitch, yaw);
 
-    if (!AP_Math::is_equal(_hil.last_declination,get_declination())) {
+    if (!is_equal(_hil.last_declination,get_declination())) {
         _setup_earth_field();
         _hil.last_declination = get_declination();
     }