diff --git a/hmm.json b/hmm.json
index 9061d594b..e92868545 100644
--- a/hmm.json
+++ b/hmm.json
@@ -89,7 +89,7 @@
     {
       "name": "json2object",
       "type": "haxelib",
-      "version": null
+      "version": "3.11.0"
     },
     {
       "name": "lime",
@@ -118,4 +118,4 @@
       "version": "0.2.2"
     }
   ]
-}
+}
\ No newline at end of file
diff --git a/source/funkin/audio/SoundGroup.hx b/source/funkin/audio/SoundGroup.hx
index df197148b..69c52c3d0 100644
--- a/source/funkin/audio/SoundGroup.hx
+++ b/source/funkin/audio/SoundGroup.hx
@@ -79,6 +79,10 @@ class SoundGroup extends FlxTypedGroup<FlxSound>
     result.pause();
     result.time = this.time;
 
+    result.onComplete = function() {
+      this.onComplete();
+    }
+
     // Apply parameters to the new sound.
     result.pitch = this.pitch;
     result.volume = this.volume;
@@ -86,6 +90,8 @@ class SoundGroup extends FlxTypedGroup<FlxSound>
     return result;
   }
 
+  public dynamic function onComplete():Void {}
+
   /**
    * Pause all the sounds in the group.
    */
diff --git a/source/funkin/play/PlayState.hx b/source/funkin/play/PlayState.hx
index 4698c7e7e..047a1b5fe 100644
--- a/source/funkin/play/PlayState.hx
+++ b/source/funkin/play/PlayState.hx
@@ -1093,7 +1093,7 @@ class PlayState extends MusicBeatState
 
     // TODO: Fix grouped vocals
     vocals = currentChart.buildVocals();
-    vocals.members[0].onComplete = function() {
+    vocals.onComplete = function() {
       vocalsFinished = true;
     }
 
diff --git a/source/funkin/play/song/Song.hx b/source/funkin/play/song/Song.hx
index 93f7d42a3..a712de1cc 100644
--- a/source/funkin/play/song/Song.hx
+++ b/source/funkin/play/song/Song.hx
@@ -305,7 +305,7 @@ class SongDifficulty
 
   public inline function playInst(volume:Float = 1.0, looped:Bool = false):Void
   {
-    var suffix:String = variation == null ? null : '-$variation';
+    var suffix:String = (variation ?? '') != '' ? '-$variation' : '';
     FlxG.sound.playMusic(Paths.inst(this.song.songId, suffix), volume, looped);
   }
 
@@ -336,7 +336,7 @@ class SongDifficulty
       return [];
     }
 
-    var suffix:String = variation != null ? '-$variation' : '';
+    var suffix:String = (variation ?? '') != '' ? '-$variation' : '';
 
     // Automatically resolve voices by removing suffixes.
     // For example, if `Voices-bf-car.ogg` does not exist, check for `Voices-bf.ogg`.