1 files changed, 1 insertions, 1 deletions
diff --git a/py/obj.h b/py/obj.h
index 2446f63754..77f7c0b8f6 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -217,7 +217,7 @@ struct _mp_obj_type_t {
     mp_binary_op_fun_t binary_op;   // can return NULL if op not supported
 
     mp_load_attr_fun_t load_attr;
-    mp_store_attr_fun_t store_attr;
+    mp_store_attr_fun_t store_attr; // if value is MP_OBJ_NULL, then delete that attribute
     // Implements container[index] = val; note that load_item is implemented
     // by binary_op(RT_BINARY_OP_SUBSCR)
     mp_store_item_fun_t store_item;