diff --git a/gfxnvidia.c b/gfxnvidia.c
index faed11d..ec04a94 100644
--- a/gfxnvidia.c
+++ b/gfxnvidia.c
@@ -104,7 +104,7 @@
 
 	/* Write/erase doesn't work. */
 	programmer_may_write = false;
-	register_par_master(&par_master_gfxnvidia, BUS_PARALLEL);
+	register_par_master(&par_master_gfxnvidia, BUS_PARALLEL, NULL);
 
 	return 0;
 }