diff --git a/clutter/clutter-drag-action.c b/clutter/clutter-drag-action.c
index 0e9ecdbab..4925b63e7 100644
--- a/clutter/clutter-drag-action.c
+++ b/clutter/clutter-drag-action.c
@@ -684,7 +684,8 @@ clutter_drag_action_new (void)
 /**
  * clutter_drag_action_set_drag_threshold:
  * @action: a #ClutterDragAction
- * @threshold: a distance, in pixels
+ * @x_threshold: a distance on the horizontal axis, in pixels
+ * @y_threshold: a distance on the vertical axis, in pixels
  *
  * Sets the horizontal and vertical drag thresholds that must be
  * cleared by the pointer before @action can begin the dragging