diff --git a/sys/src/kern/amd64/fis.c b/sys/src/kern/amd64/fis.c
index 4e4d610..d83e691 100644
--- a/sys/src/kern/amd64/fis.c
+++ b/sys/src/kern/amd64/fis.c
@@ -238,7 +238,7 @@ idfeat(Sfis *f, uint16_t *id)
 		f->feat |= Datapi;
 	i = gbit16(id + 49);
 	if((i & Ilbasp) == 0){
-		if(gbit16(id + 53) & 1){
+		if((gbit16(id + 53) & 1) == 0){
 			f->c = gbit16(id + 1);
 			f->h = gbit16(id + 3);
 			f->s = gbit16(id + 6);