diff --git a/ArduPlane/ekf_check.cpp b/ArduPlane/ekf_check.cpp
index 738f63424e..6ef7f2da00 100644
--- a/ArduPlane/ekf_check.cpp
+++ b/ArduPlane/ekf_check.cpp
@@ -110,7 +110,9 @@ bool Plane::ekf_over_threshold()
     float position_variance, vel_variance, height_variance, tas_variance;
     Vector3f mag_variance;
     Vector2f offset;
-    ahrs.get_variances(vel_variance, position_variance, height_variance, mag_variance, tas_variance, offset);
+    if (!ahrs.get_variances(vel_variance, position_variance, height_variance, mag_variance, tas_variance, offset)) {
+        return false;
+    };
 
     const float mag_max = fmaxf(fmaxf(mag_variance.x,mag_variance.y),mag_variance.z);