diff --git a/src/app/room/page.tsx b/src/app/room/page.tsx
index 92d46ca..2fa1ba9 100644
--- a/src/app/room/page.tsx
+++ b/src/app/room/page.tsx
@@ -222,9 +222,12 @@ function RoomInner() {
 
     s.on("connect", () => {
       if (sessionIdRef.current) {
-        s.emit("session:join", { sessionId: sessionIdRef.current });
+        s.emit("session:join", { sessionId: sessionIdRef.current }, (error?: string) => {
+          if (!error) setSocket(s);
+        });
+      } else {
+        setSocket(s);
       }
-      setSocket(s);
     });
 
     s.on("session:ended", () => {
diff --git a/src/socket/index.ts b/src/socket/index.ts
index 9a40487..8a5f69f 100644
--- a/src/socket/index.ts
+++ b/src/socket/index.ts
@@ -137,7 +137,7 @@ export async function initSocketIO(
     console.log(`[Socket.IO] Client connected: ${socket.id} (user: ${socket.data.userId})`);
 
     // Session room management
-    socket.on("session:join", async (payload) => {
+    socket.on("session:join", async (payload, ack) => {
       if (payload?.sessionId && typeof payload.sessionId === "string") {
         const userId = socket.data.userId;
 
@@ -149,6 +149,7 @@ export async function initSocketIO(
 
         if (!sessionRecord) {
           socket.emit("question:error", { message: "Session not found." });
+          if (typeof ack === "function") ack("Session not found.");
           return;
         }
 
@@ -173,6 +174,7 @@ export async function initSocketIO(
             reason: "not enrolled",
           });
           socket.emit("question:error", { message: "You are not enrolled in this session." });
+          if (typeof ack === "function") ack("Not enrolled.");
           return;
         }
 
@@ -192,6 +194,7 @@ export async function initSocketIO(
         }
 
         await broadcastViewerCount(payload.sessionId);
+        if (typeof ack === "function") ack();
       }
     });
 
diff --git a/src/socket/types.ts b/src/socket/types.ts
index 7f9249b..9a5df5f 100644
--- a/src/socket/types.ts
+++ b/src/socket/types.ts
@@ -165,7 +165,7 @@ export interface ViewerSyncPayload {
 export interface ClientToServerEvents {
   "question:create": (payload: QuestionCreatePayload) => void;
   "answer:create": (payload: AnswerCreatePayload) => void;
-  "session:join": (payload: SessionJoinPayload) => void;
+  "session:join": (payload: SessionJoinPayload, ack?: (error?: string) => void) => void;
   "session:leave": (payload: SessionLeavePayload) => void;
   "question:upvote": (payload: QuestionUpvotePayload) => void;
   "answer:upvote": (payload: AnswerUpvotePayload) => void;