diff --git a/crates/loro-internal/src/oplog/change_store.rs b/crates/loro-internal/src/oplog/change_store.rs
index ce07ff50..fecd3293 100644
--- a/crates/loro-internal/src/oplog/change_store.rs
+++ b/crates/loro-internal/src/oplog/change_store.rs
@@ -56,6 +56,9 @@ struct ChangeStoreInner {
     mem_parsed_kv: BTreeMap<ID, Arc<ChangesBlock>>,
 }
 
+pub const VV_KEY: &[u8] = b"vv";
+pub const FRONTIERS_KEY: &[u8] = b"fr";
+
 impl ChangeStore {
     pub fn new_mem(a: &SharedArena, merge_interval: Arc<AtomicI64>) -> Self {
         Self {
@@ -229,14 +232,26 @@ impl ChangeStore {
         }
 
         loop {
-            let old_vv_bytes = store.get(b"vv");
+            let old_vv_bytes = store.get(VV_KEY);
             let new_vv = old_vv_bytes
                 .as_ref()
                 .map(|bytes| VersionVector::decode(bytes).unwrap())
                 .unwrap_or_default();
             inner.vv.merge_vv(&new_vv);
             let vv_bytes = inner.vv.encode();
-            if store.compare_and_swap(b"vv", old_vv_bytes, vv_bytes.into()) {
+            if store.compare_and_swap(VV_KEY, old_vv_bytes, vv_bytes.into()) {
+            } else {
+                continue;
+            }
+
+            let old_frontiers_bytes = store.get(FRONTIERS_KEY);
+            let new_frontiers = old_frontiers_bytes
+                .as_ref()
+                .map(|bytes| Frontiers::decode(bytes).unwrap())
+                .unwrap_or_default();
+            inner.frontiers.merge_frontiers(&new_frontiers);
+            let frontiers_bytes = inner.frontiers.encode();
+            if store.compare_and_swap(FRONTIERS_KEY, old_frontiers_bytes, frontiers_bytes.into()) {
                 break;
             }
         }
diff --git a/crates/loro-internal/src/version.rs b/crates/loro-internal/src/version.rs
index 03a85467..d32c8a8f 100644
--- a/crates/loro-internal/src/version.rs
+++ b/crates/loro-internal/src/version.rs
@@ -203,6 +203,58 @@ impl Frontiers {
     pub(crate) fn with_capacity(cap: usize) -> Frontiers {
         Self(SmallVec::with_capacity(cap))
     }
+
+    pub(crate) fn merge_frontiers(&mut self, new_frontiers: &Frontiers) {
+        if self.len() <= 1 {
+            if self == new_frontiers {
+                return;
+            }
+
+            if new_frontiers.len() == 0 {
+                return;
+            }
+
+            if self.len() == 0 {
+                *self = new_frontiers.clone();
+                return;
+            }
+
+            if new_frontiers.len() == 1 {
+                let new_id = new_frontiers[0];
+                if self[0].peer == new_id.peer {
+                    if self[0].counter < new_id.counter {
+                        self[0].counter = new_id.counter;
+                    } else {
+                        return;
+                    }
+                } else {
+                    self.push(new_id);
+                    return;
+                }
+            }
+        }
+
+        let mut map = self
+            .0
+            .iter()
+            .map(|id| (id.peer, id.counter))
+            .collect::<FxHashMap<_, _>>();
+
+        for id in new_frontiers.0.iter() {
+            if let Some(counter) = map.get_mut(&id.peer) {
+                if *counter < id.counter {
+                    *counter = id.counter;
+                }
+            } else {
+                self.0.push(*id);
+            }
+        }
+
+        self.0 = map
+            .into_iter()
+            .map(|(peer, counter)| ID::new(peer, counter))
+            .collect();
+    }
 }
 
 impl Deref for Frontiers {