diff --git a/stand/libsa/dosfs.c b/stand/libsa/dosfs.c
index 06215b1ab0fdb7..6f7b207ff4048a 100644
--- a/stand/libsa/dosfs.c
+++ b/stand/libsa/dosfs.c
@@ -816,7 +816,7 @@ fsize(DOS_FS *fs, DOS_DE *de)
 	int n;
 
 	if (!(size = cv4(de->size)) && de->attr & FA_DIR) {
-		if (!(c = cv2(de->clus))) {
+		if (!(c = stclus(fs->fatsz, de))) {
 			size = fs->dirents * sizeof(DOS_DE);
 		} else {
 			if ((n = fatcnt(fs, c)) == -1)