diff --git a/plugins/client-resources/src/connection.ts b/plugins/client-resources/src/connection.ts
index 137740fa35..bb7b158ded 100644
--- a/plugins/client-resources/src/connection.ts
+++ b/plugins/client-resources/src/connection.ts
@@ -205,6 +205,13 @@ class Connection implements ClientConnection {
       websocket.onmessage = (event: MessageEvent) => {
         const resp = readResponse<any>(event.data, binaryResponse)
         if (resp.id === -1 && resp.result === 'hello') {
+          if ((resp as HelloResponse).alreadyConnected === true) {
+            this.sessionId = generateId()
+            if (typeof sessionStorage !== 'undefined') {
+              sessionStorage.setItem('session.id.' + this.url, this.sessionId)
+            }
+            reject(new Error('alreadyConnected'))
+          }
           if ((resp as HelloResponse).binary) {
             binaryResponse = true
           }
diff --git a/server/rpc/src/rpc.ts b/server/rpc/src/rpc.ts
index f6e5b12516..55845dd05c 100644
--- a/server/rpc/src/rpc.ts
+++ b/server/rpc/src/rpc.ts
@@ -46,6 +46,7 @@ export interface HelloRequest extends Request<any[]> {
 export interface HelloResponse extends Response<any> {
   binary: boolean
   reconnect?: boolean
+  alreadyConnected?: boolean
 }
 
 /**
diff --git a/server/ws/src/server.ts b/server/ws/src/server.ts
index e9e1f749e2..a230c86326 100644
--- a/server/ws/src/server.ts
+++ b/server/ws/src/server.ts
@@ -214,6 +214,17 @@ class TSessionManager implements SessionManager {
       let workspace = this.workspaces.get(wsString)
       await workspace?.closing
       workspace = this.workspaces.get(wsString)
+      if (sessionId !== undefined && workspace?.sessions?.has(sessionId) === true) {
+        const helloResponse: HelloResponse = {
+          id: -1,
+          result: 'hello',
+          binary: false,
+          reconnect: false,
+          alreadyConnected: true
+        }
+        await ws.send(ctx, helloResponse, false, false)
+        return { error: new Error('Session already exists') }
+      }
       const workspaceName = workspaceInfo.workspaceName ?? workspaceInfo.workspaceUrl ?? workspaceInfo.workspace
 
       if (workspace === undefined) {