diff --git a/EKF/ekf_helper.cpp b/EKF/ekf_helper.cpp
index 5f22cdf25a..12ec0a9d2e 100644
--- a/EKF/ekf_helper.cpp
+++ b/EKF/ekf_helper.cpp
@@ -42,8 +42,6 @@
 #include "ekf.h"
 #include "mathlib.h"
 
-using std::abs;
-
 // Reset the velocity states. If we have a recent and valid
 // gps measurement then use for velocity initialisation
 bool Ekf::resetVelocity()