diff --git a/frontend/src/store/index.ts b/frontend/src/store/index.ts
index 3418150..3c84188 100644
--- a/frontend/src/store/index.ts
+++ b/frontend/src/store/index.ts
@@ -53,10 +53,20 @@ export const useStore = create<AppStore>((set, get) => ({
   setChats: (chats) => set({ chats, chatsLoading: false }),
   setChatsLoading: (v) => set({ chatsLoading: v }),
 
-  updateChat: (partial) => set(state => ({
-    chats: state.chats.map(c => c.id === partial.id ? { ...c, ...partial } : c),
-    activeChat: state.activeChat?.id === partial.id ? { ...state.activeChat, ...partial } : state.activeChat,
-  })),
+  updateChat: (partial) => set(state => {
+    const updated = state.chats.map(c => c.id === partial.id ? { ...c, ...partial } : c);
+    updated.sort((a, b) => {
+      if (a.isPinned && !b.isPinned) return -1;
+      if (!a.isPinned && b.isPinned) return 1;
+      const ta = a.lastMessageAt || a.createdAt;
+      const tb = b.lastMessageAt || b.createdAt;
+      return new Date(tb).getTime() - new Date(ta).getTime();
+    });
+    return {
+      chats: updated,
+      activeChat: state.activeChat?.id === partial.id ? { ...state.activeChat, ...partial } : state.activeChat,
+    };
+  }),
 
   setActiveChat: (chat) => set({ activeChat: chat }),