diff --git a/rcore-fs-sfs/src/lib.rs b/rcore-fs-sfs/src/lib.rs
index be79aac..b9fc438 100644
--- a/rcore-fs-sfs/src/lib.rs
+++ b/rcore-fs-sfs/src/lib.rs
@@ -870,7 +870,7 @@ impl vfs::FileSystem for SimpleFileSystem {
     fn root_inode(&self) -> Arc<vfs::INode> {
         // self.get_inode(BLKN_ROOT)
         let root = self.get_inode(BLKN_ROOT);
-        root.create("dev", vfs::FileType::Dir, 0); // what's mode?
+        root.create("dev", vfs::FileType::Dir, 0).expect("fail to create dev"); // what's mode?
         return root;
     }