diff --git a/include/c64/vic.h b/include/c64/vic.h
index b8596c7..0fb37c7 100644
--- a/include/c64/vic.h
+++ b/include/c64/vic.h
@@ -49,7 +49,7 @@ struct VIC
 	byte	spr_msbx;
 
 	volatile byte	ctrl1;
-	byte	raster;
+	volatile byte	raster;
 	byte	lpx, lpy;
 	byte	spr_enable;
 	byte	ctrl2;