diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 47012c9bf505..c7ffd21fb255 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -672,7 +672,7 @@ static u32 true_sectors_per_clst(const struct NTFS_BOOT *boot)
 	if (boot->sectors_per_clusters <= 0x80)
 		return boot->sectors_per_clusters;
 	if (boot->sectors_per_clusters >= 0xf4) /* limit shift to 2MB max */
-		return 1U << (0 - boot->sectors_per_clusters);
+		return 1U << (0 - (s8) boot->sectors_per_clusters);
 	return -EINVAL;
 }