diff --git a/libraries/AP_NavEKF/AP_NavEKF.cpp b/libraries/AP_NavEKF/AP_NavEKF.cpp
index 8d57c0bdd1..52b15bc28f 100644
--- a/libraries/AP_NavEKF/AP_NavEKF.cpp
+++ b/libraries/AP_NavEKF/AP_NavEKF.cpp
@@ -1714,7 +1714,7 @@ void NavEKF::FuseVelPosNED()
             // apply an innovation consistency threshold test, but don't fail if bad IMU data
             // calculate max valid position innovation squared based on a maximum horizontal inertial nav accel error and GPS noise parameter
             // max inertial nav error is scaled with horizontal g to allow for increased errors when manoeuvring
-            float accelScale =  (1.0f + 0.1f * accNavMagHoriz);
+            float accelScale =  (1.0f + 0.1f * accNavMag);
             float maxPosInnov2 = sq(_gpsPosInnovGate * _gpsHorizPosNoise + 0.005f * accelScale * float(_gpsGlitchAccelMax) * sq(0.001f * float(imuSampleTime_ms - posFailTime)));
             posTestRatio = (sq(posInnov[0]) + sq(posInnov[1])) / maxPosInnov2;
             posHealth = ((posTestRatio < 1.0f) || badIMUdata);