diff --git a/src/MixerBoard.h b/src/MixerBoard.h
index 9fe2bc3e3..e4c895fb9 100644
--- a/src/MixerBoard.h
+++ b/src/MixerBoard.h
@@ -26,6 +26,7 @@
 
 class wxArrayString;
 class wxBitmapButton;
+class wxMemoryDC;
 class AButton;
 struct TrackListEvent;