CustomPropertyDrawer for derived class?

I am trying to display custom editor for derived class (accessed through base class pointer). I've been trying to used PropertyDrawer but that didn't seem to work.

Here's the component:

 public class Stat_Unity : MonoBehaviour
 {
     public Stat stat = new HitpointsStat { name = "abc", hitpoints = 100 };
 }

Here are my drawers:

Base class:

 [CustomPropertyDrawer(typeof(Stat))]
 public class StatEditor : PropertyDrawer
 {
     public override void OnGUI(Rect position,
                                 SerializedProperty property,
                                 GUIContent label)
     {
         EditorGUI.BeginProperty (position, label, property);
         
         var nameRect = new Rect(position.x, position.y, 30, position.height);
 
         EditorGUI.PropertyField(nameRect, property.FindPropertyRelative("name"), GUIContent.none);
 
         EditorGUI.EndProperty();
     }
 }

Derived class:

 [CustomPropertyDrawer(typeof(HitpointsStat))]
 public class HitpointStatEditor : StatEditor
 {
     public override void OnGUI(Rect position,
                                 SerializedProperty property,
                                 GUIContent label)
     {
         base.OnGUI(position, property, label);
 
         EditorGUI.BeginProperty(position, label, property);
 
         var hitpointsRect = new Rect(position.x + 35, position.y, 50, position.height);
 
         EditorGUI.PropertyField(hitpointsRect, property.FindPropertyRelative("hitpoints"), GUIContent.none);
 
         EditorGUI.EndProperty();
     }
 }

It only displays base class property drawer every time, no matter if it's actually a HitpointStat.

How can I fix this to keep base class pointer access and yet display derived class?

Thanks.