diff --git a/Tools/autotest/arduplane.py b/Tools/autotest/arduplane.py
index fd3be9736d..ee28b57a1e 100644
--- a/Tools/autotest/arduplane.py
+++ b/Tools/autotest/arduplane.py
@@ -4636,6 +4636,31 @@ class AutoTestPlane(AutoTest):
         ])
         self.start_SITL()
 
+    def MAV_CMD_GUIDED_CHANGE_ALTITUDE(self):
+        '''test handling of MAV_CMD_GUIDED_CHANGE_ALTITUDE'''
+        self.takeoff(30, relative=True)
+        self.change_mode('GUIDED')
+        for alt in 50, 70:
+            self.run_cmd_int(
+                mavutil.mavlink.MAV_CMD_GUIDED_CHANGE_ALTITUDE,
+                p7=alt,
+                frame=mavutil.mavlink.MAV_FRAME_GLOBAL_RELATIVE_ALT,
+            )
+            self.wait_altitude(alt-1, alt+1, timeout=30, relative=True)
+
+        # test for #24535
+        self.change_mode('LOITER')
+        self.delay_sim_time(5)
+        self.change_mode('GUIDED')
+        self.wait_altitude(
+            alt-3,  # NOTE: reuse of alt from above loop!
+            alt+3,
+            minimum_duration=10,
+            timeout=30,
+            relative=True,
+        )
+        self.fly_home_land_and_disarm()
+
     def tests(self):
         '''return list of all tests'''
         ret = super(AutoTestPlane, self).tests()
@@ -4725,6 +4750,7 @@ class AutoTestPlane(AutoTest):
             self.NoArmWithoutMissionItems,
             self.MODE_SWITCH_RESET,
             self.ExternalPositionEstimate,
+            self.MAV_CMD_GUIDED_CHANGE_ALTITUDE,
         ])
         return ret