diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index 598f058670595708cf90dd4ee230fc4a63a3e6f7..fa51ed649968e7fba6312d11245701ff69ba4095 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -381,7 +381,8 @@ static int nilfs_btree_root_broken(const struct nilfs_btree_node *node,
 	if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN ||
 		     level >= NILFS_BTREE_LEVEL_MAX ||
 		     nchildren < 0 ||
-		     nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX)) {
+		     nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX ||
+		     (nchildren == 0 && level > NILFS_BTREE_LEVEL_NODE_MIN))) {
 		nilfs_crit(inode->i_sb,
 			   "bad btree root (ino=%lu): level = %d, flags = 0x%x, nchildren = %d",
 			   inode->i_ino, level, flags, nchildren);