diff --git a/src/mess/drivers/casloopy.c b/src/mess/drivers/casloopy.c
index ebaf2965e7a..50241499dc7 100644
--- a/src/mess/drivers/casloopy.c
+++ b/src/mess/drivers/casloopy.c
@@ -264,7 +264,7 @@ UINT32 casloopy_state::screen_update_casloopy(screen_device &screen, bitmap_ind1
 
 			tile &= 0x7ff; //???
 
-			drawgfx_transpen(bitmap,cliprect,gfx,tile,7,0,0,x*8,y*8,-1);
+			drawgfx_transpen(bitmap,cliprect,gfx,tile,7,0,0,x*8,y*8,0xffffffff);
 
 			count+=2;
 		}