diff --git a/ArduPlane/navigation.cpp b/ArduPlane/navigation.cpp
index 22d97b8aab..1a26dfe9a9 100644
--- a/ArduPlane/navigation.cpp
+++ b/ArduPlane/navigation.cpp
@@ -163,6 +163,8 @@ void Plane::calc_gndspeed_undershoot()
             float gndSpdFwd = yawVect * gndVel;
             groundspeed_undershoot = (aparm.min_gndspeed_cm > 0) ? (aparm.min_gndspeed_cm - gndSpdFwd*100) : 0;
         }
+    } else {
+    	groundspeed_undershoot = 0;
     }
 }