diff --git a/src/signal_server.cpp b/src/signal_server.cpp
index e4bc8ec..1e5b7fb 100644
--- a/src/signal_server.cpp
+++ b/src/signal_server.cpp
@@ -198,7 +198,9 @@ void SignalServer::on_message(websocketpp::connection_hdl hdl,
       std::string transmission_id = j["transmission_id"].get<std::string>();
       std::string password = j["password"].get<std::string>();
 
-      if (transmission_manager_.CheckPassword(password, transmission_id)) {
+      int ret = transmission_manager_.CheckPassword(password, transmission_id);
+
+      if (0 == ret) {
         std::vector<std::string> user_id_list =
             transmission_manager_.GetAllUserIdOfTransmission(transmission_id);
 
@@ -208,7 +210,7 @@ void SignalServer::on_message(websocketpp::connection_hdl hdl,
                         {"status", "success"}};
 
         send_msg(hdl, message);
-      } else {
+      } else if (-1 == ret) {
         std::vector<std::string> user_id_list;
         json message = {{"type", "user_id_list"},
                         {"transmission_id", transmission_id},
@@ -221,6 +223,20 @@ void SignalServer::on_message(websocketpp::connection_hdl hdl,
         //     password, transmission_id,
         //     transmission_manager_.GetPassword(transmission_id));
 
+        send_msg(hdl, message);
+      } else if (-2 == ret) {
+        std::vector<std::string> user_id_list;
+        json message = {{"type", "user_id_list"},
+                        {"transmission_id", transmission_id},
+                        {"user_id_list", user_id_list},
+                        {"status", "failed"},
+                        {"reason", "No such transmission id"}};
+        // LOG_INFO(
+        //     "Incorrect password [{}] for transmission [{}] with password is "
+        //     "[{}]",
+        //     password, transmission_id,
+        //     transmission_manager_.GetPassword(transmission_id));
+
         send_msg(hdl, message);
       }
 
diff --git a/src/transmission_manager.cpp b/src/transmission_manager.cpp
index deb8580..2bf7329 100644
--- a/src/transmission_manager.cpp
+++ b/src/transmission_manager.cpp
@@ -145,15 +145,15 @@ std::string TransmissionManager::GetUserId(websocketpp::connection_hdl hdl) {
   return "";
 }
 
-bool TransmissionManager::CheckPassword(const std::string& password,
-                                        const std::string& transmission_id) {
+int TransmissionManager::CheckPassword(const std::string& password,
+                                       const std::string& transmission_id) {
   if (transmission_password_list_.find(transmission_id) ==
       transmission_password_list_.end()) {
     LOG_ERROR("No transmission with id [{}]", transmission_id);
-    return false;
+    return -2;
   }
 
-  return transmission_password_list_[transmission_id] == password;
+  return transmission_password_list_[transmission_id] == password ? 0 : -1;
 }
 
 std::string TransmissionManager::GetPassword(
diff --git a/src/transmission_manager.h b/src/transmission_manager.h
index 499e4ff..edff5bb 100644
--- a/src/transmission_manager.h
+++ b/src/transmission_manager.h
@@ -28,8 +28,8 @@ class TransmissionManager {
 
   websocketpp::connection_hdl GetWsHandle(const std::string& user_id);
   std::string GetUserId(websocketpp::connection_hdl hdl);
-  bool CheckPassword(const std::string& password,
-                     const std::string& transmission_id);
+  int CheckPassword(const std::string& password,
+                    const std::string& transmission_id);
   std::string GetPassword(const std::string& transmission_id);
 
  private: