diff --git a/drivers/video/tridentfb.c b/drivers/video/tridentfb.c
index af02af1..f3153a8 100644
--- a/drivers/video/tridentfb.c
+++ b/drivers/video/tridentfb.c
@@ -680,8 +680,8 @@
 		vga_mm_wseq(par->io_virt, ClockHigh, hi);
 		vga_mm_wseq(par->io_virt, ClockLow, lo);
 	} else {
-		outb(lo, 0x43C8);
-		outb(hi, 0x43C9);
+		t_outb(par, lo, 0x43C8);
+		t_outb(par, hi, 0x43C9);
 	}
 	debug("VCLK = %X %X\n", hi, lo);
 }