diff --git a/libraries/AC_AttitudeControl/AC_PosControl.cpp b/libraries/AC_AttitudeControl/AC_PosControl.cpp
index 7a14bd92c5..fa7fbd6978 100644
--- a/libraries/AC_AttitudeControl/AC_PosControl.cpp
+++ b/libraries/AC_AttitudeControl/AC_PosControl.cpp
@@ -378,7 +378,7 @@ void AC_PosControl::pos_to_rate_z()
     }
 
     // calculate _vel_target.z using from _pos_error.z using sqrt controller
-    _vel_target.z = AC_AttitudeControl::sqrt_controller(_pos_error.z, _p_pos_z.kP(), _accel_z_cms);
+    _vel_target.z = AC_AttitudeControl::sqrt_controller(_pos_error.z, _p_pos_z.kP(), _accel_z_cms, _dt);
 
     // check speed limits
     // To-Do: check these speed limits here or in the pos->rate controller