diff --git a/MainWindow.xaml.cs b/MainWindow.xaml.cs
index 16895e71..f7262a21 100644
--- a/MainWindow.xaml.cs
+++ b/MainWindow.xaml.cs
@@ -814,6 +814,7 @@ namespace GARbro.GUI
                     {
                         m_audio.PlaybackStopped -= OnPlaybackStopped;
                         m_audio.Dispose();
+                        m_audio = null;
                     }
                     var wave_stream = new WaveStreamImpl (sound);
                     m_audio = new WaveOutEvent();