diff --git a/crates/loro-internal/src/handler/tree.rs b/crates/loro-internal/src/handler/tree.rs
index 853ba90a..b520c8f0 100644
--- a/crates/loro-internal/src/handler/tree.rs
+++ b/crates/loro-internal/src/handler/tree.rs
@@ -615,17 +615,16 @@ impl TreeHandler {
     }
 
     // TODO: iterator
-    pub fn children(&self, parent: Option<TreeID>) -> Vec<TreeID> {
+    pub fn children(&self, parent: Option<TreeID>) -> Option<Vec<TreeID>> {
         match &self.inner {
             MaybeDetached::Detached(t) => {
                 let t = t.try_lock().unwrap();
-                t.value.get_children(parent).unwrap()
+                t.value.get_children(parent)
             }
             MaybeDetached::Attached(a) => a.with_state(|state| {
                 let a = state.as_tree_state().unwrap();
                 a.get_children(&TreeParentId::from(parent))
-                    .unwrap()
-                    .collect()
+                    .map(|x| x.collect())
             }),
         }
     }
@@ -696,7 +695,7 @@ impl TreeHandler {
     }
 
     pub fn roots(&self) -> Vec<TreeID> {
-        self.children(None)
+        self.children(None).unwrap_or_default()
     }
 
     #[allow(non_snake_case)]
diff --git a/crates/loro-wasm/src/lib.rs b/crates/loro-wasm/src/lib.rs
index 5fb09f6f..972d19bd 100644
--- a/crates/loro-wasm/src/lib.rs
+++ b/crates/loro-wasm/src/lib.rs
@@ -2939,7 +2939,7 @@ impl LoroTreeNode {
     /// the WASM boundary.
     #[wasm_bindgen(skip_typescript)]
     pub fn children(&self) -> Array {
-        let children = self.tree.children(Some(self.id));
+        let children = self.tree.children(Some(self.id)).unwrap_or_default();
         let children = children.into_iter().map(|c| {
             let node = LoroTreeNode::from_tree(c, self.tree.clone(), self.doc.clone());
             JsValue::from(node)
diff --git a/crates/loro/src/lib.rs b/crates/loro/src/lib.rs
index 34796674..f89c0ca1 100644
--- a/crates/loro/src/lib.rs
+++ b/crates/loro/src/lib.rs
@@ -11,9 +11,7 @@ use loro_internal::cursor::Side;
 use loro_internal::encoding::ImportBlobMetadata;
 use loro_internal::handler::HandlerTrait;
 use loro_internal::handler::ValueOrHandler;
-use loro_internal::loro::CommitOptions;
 use loro_internal::undo::{OnPop, OnPush};
-use loro_internal::JsonSchema;
 use loro_internal::LoroDoc as InnerLoroDoc;
 use loro_internal::OpLog;
 
@@ -40,10 +38,12 @@ pub use loro_internal::delta::{TreeDeltaItem, TreeDiff, TreeExternalDiff};
 pub use loro_internal::event::Index;
 pub use loro_internal::handler::TextDelta;
 pub use loro_internal::id::{PeerID, TreeID, ID};
+pub use loro_internal::loro::CommitOptions;
 pub use loro_internal::obs::SubID;
 pub use loro_internal::oplog::FrontiersNotIncluded;
 pub use loro_internal::undo;
 pub use loro_internal::version::{Frontiers, VersionVector};
+pub use loro_internal::JsonSchema;
 pub use loro_internal::UndoManager as InnerUndoManager;
 pub use loro_internal::{loro_value, to_value};
 pub use loro_internal::{LoroError, LoroResult, LoroValue, ToJson};
@@ -1368,7 +1368,7 @@ impl LoroTree {
     }
 
     /// Return all children of the target node.
-    pub fn children(&self, parent: Option<TreeID>) -> Vec<TreeID> {
+    pub fn children(&self, parent: Option<TreeID>) -> Option<Vec<TreeID>> {
         self.handler.children(parent)
     }