diff --git a/gdk/gdkcairo.c b/gdk/gdkcairo.c
index 61bfd3cb01..4e7c8ffcb1 100644
--- a/gdk/gdkcairo.c
+++ b/gdk/gdkcairo.c
@@ -418,8 +418,9 @@ _gdk_cairo_surface_extents (cairo_surface_t *surface,
  * is more than 50% opaque. This function takes into account device
  * offsets that might be set with cairo_surface_set_device_offset().
  *
- * Returns: A new region
- **/
+ * Returns: A #cairo_region_t. This must be freed with cairo_region_destroy()
+ *   when you are done.
+ */
 cairo_region_t *
 gdk_cairo_region_create_from_surface (cairo_surface_t *surface)
 {