diff --git a/sbin/newfs_nandfs/newfs_nandfs.c b/sbin/newfs_nandfs/newfs_nandfs.c
index fda2b9ed01ef..3990dbbba8fd 100644
--- a/sbin/newfs_nandfs/newfs_nandfs.c
+++ b/sbin/newfs_nandfs/newfs_nandfs.c
@@ -897,7 +897,7 @@ check_parameters(void)
 		    NANDFS_SEG_MIN_BLOCKS);
 
 	/* check reserved segment percentage */
-	if ((rsv_segment_percent < 1) && (rsv_segment_percent > 99))
+	if ((rsv_segment_percent < 1) || (rsv_segment_percent > 99))
 		errx(1, "Bad reserved segment percentage. "
 		    "Must in range 1..99.");