diff --git a/desktop/renderer-app/src/pages/utils/join-room-handler.ts b/desktop/renderer-app/src/pages/utils/join-room-handler.ts
index f5df2cbecbc..72296d99753 100644
--- a/desktop/renderer-app/src/pages/utils/join-room-handler.ts
+++ b/desktop/renderer-app/src/pages/utils/join-room-handler.ts
@@ -1,4 +1,4 @@
-import { RequestErrorCode, RoomType, isPmiRoom } from "@netless/flat-server-api";
+import { RequestErrorCode, RoomType } from "@netless/flat-server-api";
 import { roomStore, globalStore } from "@netless/flat-stores";
 import { errorTips, message } from "flat-components";
 import { FlatI18n } from "@netless/flat-i18n";
@@ -37,10 +37,7 @@ export const joinRoomHandler = async (
         }
     } catch (e) {
         // if room not found and is pmi room, show wait for teacher to enter
-        if (
-            e.message.indexOf(RequestErrorCode.RoomNotFound) > -1 &&
-            (await checkPmiRoom(formatRoomUUID))
-        ) {
+        if (e.message.includes(RequestErrorCode.RoomNotFoundAndIsPmi)) {
             void message.info(FlatI18n.t("wait-for-teacher-to-enter"));
             return;
         }
@@ -48,7 +45,3 @@ export const joinRoomHandler = async (
         errorTips(e);
     }
 };
-
-async function checkPmiRoom(uuid: string): Promise<boolean> {
-    return /^[0-9]*$/.test(uuid.replace(/\s+/g, "")) && (await isPmiRoom({ pmi: uuid }))?.result;
-}
diff --git a/packages/flat-pages/src/utils/join-room-handler.ts b/packages/flat-pages/src/utils/join-room-handler.ts
index 371751a28ed..0304e177532 100644
--- a/packages/flat-pages/src/utils/join-room-handler.ts
+++ b/packages/flat-pages/src/utils/join-room-handler.ts
@@ -1,6 +1,6 @@
 import { RouteNameType, usePushHistory } from "../utils/routes";
 import { roomStore, globalStore } from "@netless/flat-stores";
-import { RequestErrorCode, RoomType, isPmiRoom } from "@netless/flat-server-api";
+import { RequestErrorCode, RoomType } from "@netless/flat-server-api";
 import { errorTips, message } from "flat-components";
 import { FlatI18n } from "@netless/flat-i18n";
 
@@ -36,10 +36,7 @@ export const joinRoomHandler = async (
         }
     } catch (e) {
         // if room not found and is pmi room, show wait for teacher to enter
-        if (
-            e.message.indexOf(RequestErrorCode.RoomNotFound) > -1 &&
-            (await checkPmiRoom(formatRoomUUID))
-        ) {
+        if (e.message.includes(RequestErrorCode.RoomNotFoundAndIsPmi)) {
             void message.info(FlatI18n.t("wait-for-teacher-to-enter"));
             return;
         }
@@ -47,7 +44,3 @@ export const joinRoomHandler = async (
         errorTips(e);
     }
 };
-
-async function checkPmiRoom(uuid: string): Promise<boolean> {
-    return /^[0-9]*$/.test(uuid.replace(/\s+/g, "")) && (await isPmiRoom({ pmi: uuid }))?.result;
-}
diff --git a/packages/flat-server-api/src/error.ts b/packages/flat-server-api/src/error.ts
index ffda75dec0c..a8a28a519df 100644
--- a/packages/flat-server-api/src/error.ts
+++ b/packages/flat-server-api/src/error.ts
@@ -24,6 +24,7 @@ export enum RequestErrorCode {
     RoomNotIsEnded,
     RoomNotIsIdle,
     RoomExists, // (pmi) room already exists, cannot create new room
+    RoomNotFoundAndIsPmi, // room not found and the invite code is pmi
 
     PeriodicNotFound = 300000,
     PeriodicIsEnded,
@@ -103,6 +104,7 @@ export const RequestErrorMessage = {
     [RequestErrorCode.RoomNotIsEnded]: "the-room-is-not-over-yet",
     [RequestErrorCode.RoomNotIsIdle]: "the-room-has-not-yet-started",
     [RequestErrorCode.RoomExists]: "the-pmi-room-already-exists",
+    [RequestErrorCode.RoomNotFoundAndIsPmi]: "wait-for-teacher-to-enter",
 
     [RequestErrorCode.PeriodicNotFound]: "periodic-rooms-do-not-exist",
     [RequestErrorCode.PeriodicIsEnded]: "periodic-rooms-have-ended",