diff --git a/conf/airframes/examples/quadrotor_lisa_m_2_pwm_spektrum.xml b/conf/airframes/examples/quadrotor_lisa_m_2_pwm_spektrum.xml
index 521baf363c7..178d2e822e5 100644
--- a/conf/airframes/examples/quadrotor_lisa_m_2_pwm_spektrum.xml
+++ b/conf/airframes/examples/quadrotor_lisa_m_2_pwm_spektrum.xml
@@ -182,7 +182,7 @@
     <!-- BOOZ_SPEED_I_OF_F(1.5) * 20% -->
     <define name="RC_CLIMB_DEAD_BAND" value ="160000"/>
     <!-- NOMINAL_HOVER_THROTTLE sets a fixed value instead of the adaptive estimation -->
-    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5"/-->
+    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5" unit="%"/-->
   </section>
 
   <section name="GUIDANCE_H" prefix="GUIDANCE_H_">
diff --git a/conf/airframes/examples/quadrotor_lisa_m_mkk.xml b/conf/airframes/examples/quadrotor_lisa_m_mkk.xml
index 08c520088b3..b1a6ff1ed6f 100644
--- a/conf/airframes/examples/quadrotor_lisa_m_mkk.xml
+++ b/conf/airframes/examples/quadrotor_lisa_m_mkk.xml
@@ -166,7 +166,7 @@
     <!-- BOOZ_SPEED_I_OF_F(1.5) * 20% -->
     <define name="RC_CLIMB_DEAD_BAND" value ="160000"/>
     <!-- NOMINAL_HOVER_THROTTLE sets a fixed value instead of the adaptive estimation -->
-    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5"/-->
+    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5" unit="%"/-->
   </section>
 
   <section name="GUIDANCE_H" prefix="GUIDANCE_H_">
diff --git a/conf/airframes/fraser_lisa_m_rotorcraft.xml b/conf/airframes/fraser_lisa_m_rotorcraft.xml
index c39584daec0..b63e27288a5 100644
--- a/conf/airframes/fraser_lisa_m_rotorcraft.xml
+++ b/conf/airframes/fraser_lisa_m_rotorcraft.xml
@@ -193,7 +193,7 @@
     <define name="RC_CLIMB_COEF" value ="163"/>
     <!-- BOOZ_SPEED_I_OF_F(1.5) * 20% -->
     <define name="RC_CLIMB_DEAD_BAND" value ="160000"/>
-    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5"/-->
+    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5" unit="%"/-->
   </section>
 
   <section name="GUIDANCE_H" prefix="GUIDANCE_H_">
diff --git a/conf/airframes/mm/rotor/quadrotor_lisa_l_mkk.xml b/conf/airframes/mm/rotor/quadrotor_lisa_l_mkk.xml
index 2d98f234b70..b88cca03f99 100644
--- a/conf/airframes/mm/rotor/quadrotor_lisa_l_mkk.xml
+++ b/conf/airframes/mm/rotor/quadrotor_lisa_l_mkk.xml
@@ -205,7 +205,7 @@
     <define name="RC_CLIMB_COEF" value ="163"/>
     <!-- BOOZ_SPEED_I_OF_F(1.5) * 20% -->
     <define name="RC_CLIMB_DEAD_BAND" value ="160000"/>
-    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5"/-->
+    <!--define name="NOMINAL_HOVER_THROTTLE" value="0.5" unit="%"/-->
   </section>
 
   <section name="GUIDANCE_H" prefix="GUIDANCE_H_">
diff --git a/conf/settings/control/rotorcraft_guidance.xml b/conf/settings/control/rotorcraft_guidance.xml
index 73e03f6d800..ab508518953 100644
--- a/conf/settings/control/rotorcraft_guidance.xml
+++ b/conf/settings/control/rotorcraft_guidance.xml
@@ -7,7 +7,7 @@
       <dl_setting var="guidance_v_kp" min="0" step="1" max="600"   module="guidance/guidance_v" shortname="kp" param="GUIDANCE_V_HOVER_KP"/>
       <dl_setting var="guidance_v_kd" min="0" step="1" max="600"   module="guidance/guidance_v" shortname="kd" param="GUIDANCE_V_HOVER_KD"/>
       <dl_setting var="guidance_v_ki" min="0" step="1" max="300"   module="guidance/guidance_v" shortname="ki" handler="SetKi" param="GUIDANCE_V_HOVER_KI"/>
-      <dl_setting var="guidance_v_nominal_throttle" min="0.1" step="0.01" max="0.9" module="guidance/guidance_v" shortname="nominal_throttle" handler="SetNominalHoverThrottle" alt_unit="%" alt_unit_coef="0.000104167" param="GUIDANCE_V_NOMINAL_HOVER_THROTTLE"/>
+      <dl_setting var="guidance_v_nominal_throttle" min="0.1" step="0.01" max="0.9" module="guidance/guidance_v" shortname="nominal_throttle" handler="SetNominalHoverThrottle" unit="pprz" alt_unit="%" param="GUIDANCE_V_NOMINAL_HOVER_THROTTLE"/>
       <dl_setting var="guidance_v_z_sp" min="-5" step="0.5" max="3" module="guidance/guidance_v" shortname="sp" unit="2e-8m" alt_unit="m" alt_unit_coef="0.00390625"/>
       <dl_setting var="ins_vf_realign" min="0" step="1" max="1" module="subsystems/ins" shortname="vf_realign" values="OFF|ON"/>
    </dl_settings>
diff --git a/conf/units.xml b/conf/units.xml
index 022537d5291..0c0c532c706 100644
--- a/conf/units.xml
+++ b/conf/units.xml
@@ -15,4 +15,6 @@
   <unit from="mm/s" to="m/s" coef="0.001"/>
   <unit from="decideg" to="deg" coef="0.1"/>
   <unit from="deg" to="decideg" coef="10."/>
+  <unit from="pprz" to="%" coef="0.000104167"/>
+  <unit from="%" to="pprz" coef="9600."/>
 </units>