diff --git a/libsrc/atari/graphics.s b/libsrc/atari/graphics.s
index 57ef2b07a..1f3d62d6f 100644
--- a/libsrc/atari/graphics.s
+++ b/libsrc/atari/graphics.s
@@ -70,6 +70,7 @@ iocbok:	txa
 	ldx	#0
 	lda	tmp2		; get fd used
 	jsr	fdtoiocb
+	tax
 
 doopen:	txa
 	;brk