diff --git a/EKF/covariance.cpp b/EKF/covariance.cpp
index ca491ced0a..105a692602 100644
--- a/EKF/covariance.cpp
+++ b/EKF/covariance.cpp
@@ -44,8 +44,6 @@
 #include <math.h>
 #include <mathlib/mathlib.h>
 
-#define sq(_arg)	powf(_arg, 2.0f)
-
 void Ekf::initialiseCovariance()
 {
 	for (unsigned i = 0; i < _k_num_states; i++) {
diff --git a/EKF/ekf.h b/EKF/ekf.h
index 726d1ffa60..9b7ebc285f 100644
--- a/EKF/ekf.h
+++ b/EKF/ekf.h
@@ -42,8 +42,6 @@
 
 #include "estimator_interface.h"
 
-#define sq(_arg)	powf(_arg, 2.0f)
-
 class Ekf : public EstimatorInterface
 {
 public:
@@ -202,4 +200,10 @@ private:
 
 	// Determine if we are airborne or motors are armed
 	void calculateVehicleStatus();
+
+	// return the square of two foating point numbers - used in autocoded sections
+	inline float sq(float var)
+	{
+		return var * var;
+	}
 };