diff --git a/src/ui/window.rs b/src/ui/window.rs
index 358e815..a376aff 100644
--- a/src/ui/window.rs
+++ b/src/ui/window.rs
@@ -25,8 +25,8 @@ mod imp {
         #[property(get, set, nullable)]
         playing_cover_art: RefCell<Option<gdk::Paintable>>,
 
-        #[property(get, set, nullable)]
-        song: RefCell<Option<PlaybinSong>>,
+        #[property(type = Option<PlaybinSong>, get = Self::song, nullable)]
+        _song: (),
 
         pub(super) setup: crate::ui::Setup,
 
@@ -70,7 +70,7 @@ mod imp {
                 play_queue: Default::default(),
                 can_click_shuffle_all: Cell::new(false),
                 playing_cover_art: Default::default(),
-                song: Default::default(),
+                _song: (),
                 setup: Default::default(),
                 api: Default::default(),
                 mpv,
@@ -139,14 +139,14 @@ mod imp {
                             },
 
                             Event::StartFile(_) => {
-                                let song: PlaybinSong = window
-                                    .playlist_model()
-                                    .item(window.playlist_pos() as u32)
-                                    .unwrap()
-                                    .dynamic_cast()
-                                    .unwrap();
-                                window.set_song(Some(&song));
+                                window.notify("song");
                                 // TODO: load cover art
+
+                                // sanity check
+                                assert_eq!(
+                                    window.song().unwrap().stream_url(),
+                                    window.imp().mpv.get_property::<String>("path").unwrap()
+                                );
                             }
 
                             Event::Hook(event) => match event.reply_userdata {
@@ -298,6 +298,21 @@ mod imp {
             }
             .unwrap()
         }
+
+        fn song(&self) -> Option<PlaybinSong> {
+            if self.obj().playlist_pos() < 0 {
+                None
+            } else {
+                Some(
+                    self.obj()
+                        .playlist_model()
+                        .item(self.obj().playlist_pos() as u32)
+                        .unwrap()
+                        .dynamic_cast()
+                        .unwrap(),
+                )
+            }
+        }
     }
 
     impl Drop for Window {