diff --git a/scumm/smush/smush_player.h b/scumm/smush/smush_player.h
index 9b29616ac49..e5dbd0a5507 100644
--- a/scumm/smush/smush_player.h
+++ b/scumm/smush/smush_player.h
@@ -67,7 +67,7 @@ public:
 
 	int _width, _height;
 	byte *_data;
-	bool _smushProcessFrame;
+	volatile bool _smushProcessFrame;
 	bool _updateNeeded;
 
 	SmushPlayer(Scumm *, int, bool);