diff --git a/sw/airborne/subsystems/nav.c b/sw/airborne/subsystems/nav.c
index beb3279d29..53c5384702 100644
--- a/sw/airborne/subsystems/nav.c
+++ b/sw/airborne/subsystems/nav.c
@@ -208,8 +208,8 @@ static inline void nav_follow(uint8_t _ac_id, float _distance, float _height);
 static void nav_ground_speed_loop( void ) {
   if (MINIMUM_AIRSPEED < nav_ground_speed_setpoint
       && nav_ground_speed_setpoint < MAXIMUM_AIRSPEED) {
-    float err = estimator_hspeed_mod - nav_ground_speed_setpoint;
-    v_ctl_auto_throttle_cruise_throttle -= nav_ground_speed_pgain*err;
+    float err = nav_ground_speed_setpoint - estimator_hspeed_mod;
+    v_ctl_auto_throttle_cruise_throttle += nav_ground_speed_pgain*err;
     Bound(v_ctl_auto_throttle_cruise_throttle, V_CTL_AUTO_THROTTLE_MIN_CRUISE_THROTTLE, V_CTL_AUTO_THROTTLE_MAX_CRUISE_THROTTLE);
   } else {
     /* Reset cruise throttle to nominal value */