diff --git a/libraries/APM_Control/AR_AttitudeControl.cpp b/libraries/APM_Control/AR_AttitudeControl.cpp
index 60312bc19c..ab5b99ee4e 100644
--- a/libraries/APM_Control/AR_AttitudeControl.cpp
+++ b/libraries/APM_Control/AR_AttitudeControl.cpp
@@ -462,7 +462,7 @@ bool AR_AttitudeControl::get_forward_speed(float &speed) const
     return true;
 }
 
-float AR_AttitudeControl::get_decel_max()
+float AR_AttitudeControl::get_decel_max() const
 {
     if (is_positive(_throttle_decel_max)) {
         return _throttle_decel_max;
@@ -507,7 +507,7 @@ float AR_AttitudeControl::get_desired_speed_accel_limited(float desired_speed, f
 }
 
 // get minimum stopping distance (in meters) given a speed (in m/s)
-float AR_AttitudeControl::get_stopping_distance(float speed)
+float AR_AttitudeControl::get_stopping_distance(float speed) const
 {
     // get maximum vehicle deceleration
     const float accel_max = get_accel_max();
diff --git a/libraries/APM_Control/AR_AttitudeControl.h b/libraries/APM_Control/AR_AttitudeControl.h
index af03ad1405..a86a37168b 100644
--- a/libraries/APM_Control/AR_AttitudeControl.h
+++ b/libraries/APM_Control/AR_AttitudeControl.h
@@ -93,7 +93,7 @@ public:
     float get_accel_max() const { return MAX(_throttle_accel_max, 0.0f); }
 
     // get throttle/speed controller maximum deceleration
-    float get_decel_max();
+    float get_decel_max() const;
 
     // get latest desired speed recorded during call to get_throttle_out_speed.  For reporting purposes only
     float get_desired_speed() const;
@@ -102,7 +102,7 @@ public:
     float get_desired_speed_accel_limited(float desired_speed, float dt) const;
 
     // get minimum stopping distance (in meters) given a speed (in m/s)
-    float get_stopping_distance(float speed);
+    float get_stopping_distance(float speed) const;
 
     // parameter var table
     static const struct AP_Param::GroupInfo var_info[];