diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -584,6 +584,8 @@
 			if (rw == UIO_READ) {
 				rl_cookie = vn_rangelock_rlock(vp, offset,
 				    offset + len);
+			} else if ((ioflg & IO_APPEND) != 0) {
+				rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
 			} else {
 				rl_cookie = vn_rangelock_wlock(vp, offset,
 				    offset + len);