diff --git a/sys/nfsclient/nfs_vfsops.c b/sys/nfsclient/nfs_vfsops.c
index 79659d04ddba..8498ee45526c 100644
--- a/sys/nfsclient/nfs_vfsops.c
+++ b/sys/nfsclient/nfs_vfsops.c
@@ -1408,10 +1408,20 @@ nfs_sync(struct mount *mp, int waitfor)
 
 	td = curthread;
 
+	MNT_ILOCK(mp);
+	/*
+	 * If a forced dismount is in progress, return from here so that
+	 * the umount(2) syscall doesn't get stuck in VFS_SYNC() before
+	 * calling VFS_UNMOUNT().
+	 */
+	if ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0) {
+		MNT_IUNLOCK(mp);
+		return (EBADF);
+	}
+
 	/*
 	 * Force stale buffer cache information to be flushed.
 	 */
-	MNT_ILOCK(mp);
 loop:
 	MNT_VNODE_FOREACH(vp, mp, mvp) {
 		VI_LOCK(vp);