diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 75a8daacb4c4..757a713bad41 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -685,7 +685,9 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
  * @p_def:     The control's default value.
  *
  * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
- * to the @p_def field.
+ * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
+ * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
+ * compound control should be all zeroes.
  *
  */
 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,