diff --git a/clutter/clutter-main.c b/clutter/clutter-main.c
index f48384909..9cb4fd066 100644
--- a/clutter/clutter-main.c
+++ b/clutter/clutter-main.c
@@ -572,6 +572,7 @@ _clutter_do_pick (ClutterStage   *stage,
                         "The time spent issuing a read pixels",
                         0 /* no application private data */);
 
+  g_return_val_if_fail (CLUTTER_IS_STAGE (stage), NULL);
 
   if (clutter_debug_flags & CLUTTER_DEBUG_NOP_PICKING)
     return CLUTTER_ACTOR (stage);