diff --git a/sound/pci/au88x0/au88x0_synth.c b/sound/pci/au88x0/au88x0_synth.c
index 2805e34bd41..8bef47311e4 100644
--- a/sound/pci/au88x0/au88x0_synth.c
+++ b/sound/pci/au88x0/au88x0_synth.c
@@ -58,7 +58,7 @@ static void vortex_wt_setdsout(vortex_t * vortex, u32 wt, int en)
 	if (en)
 		temp |= (1 << (wt & 0x1f));
 	else
-		temp &= (1 << ~(wt & 0x1f));
+		temp &= ~(1 << (wt & 0x1f));
 	hwwrite(vortex->mmio, WT_DSREG((wt >= 0x20) ? 1 : 0), temp);
 }