diff --git a/packages/xo-server/src/index.mjs b/packages/xo-server/src/index.mjs
index 1f957d2ee..e7f848a71 100644
--- a/packages/xo-server/src/index.mjs
+++ b/packages/xo-server/src/index.mjs
@@ -554,18 +554,11 @@ const setUpApi = (webServer, xo, config) => {
   })
   xo.hooks.on('stop', () => fromCallback.call(webSocketServer, 'close'))
 
-  let n = 0
-
   const onConnection = (socket, upgradeReq) => {
     const { remoteAddress } = upgradeReq.socket
 
-    ++n
-
-    log.info(`+ WebSocket connection (${remoteAddress}) (${n} connected)`)
-
     // Create the abstract XO object for this connection.
-    const connection = xo.createUserConnection()
-    connection.set('user_ip', remoteAddress)
+    const connection = xo.createUserConnection(remoteAddress)
     connection.once('close', () => {
       socket.close()
     })
@@ -580,9 +573,6 @@ const setUpApi = (webServer, xo, config) => {
 
     // Close the XO connection with this WebSocket.
     socket.once('close', () => {
-      --n
-      log.info(`- WebSocket connection (${remoteAddress}) (${n} connected)`)
-
       connection.close()
     })
 
diff --git a/packages/xo-server/src/xo.mjs b/packages/xo-server/src/xo.mjs
index 958a1092f..d153cf8e1 100644
--- a/packages/xo-server/src/xo.mjs
+++ b/packages/xo-server/src/xo.mjs
@@ -40,8 +40,7 @@ export default class Xo extends EventEmitter {
     this._objects.createIndex('byRef', new XoUniqueIndex('_xapiRef'))
 
     // Connections to users.
-    this._nextConId = 0
-    this._connections = { __proto__: null }
+    this._connections = new Set()
 
     this._httpRequestWatchers = { __proto__: null }
 
@@ -125,17 +124,21 @@ export default class Xo extends EventEmitter {
 
   // -----------------------------------------------------------------
 
-  createUserConnection() {
+  createUserConnection(remoteAddress) {
     const { _connections: connections } = this
 
     const connection = new Connection()
-    const id = (connection.id = this._nextConId++)
+    connection.set('user_ip', remoteAddress)
 
-    connections[id] = connection
+    connections.add(connection)
     connection.on('close', () => {
-      delete connections[id]
+      connections.delete(connection)
+
+      log.info(`- WebSocket connection (${remoteAddress}) (${connections.size} connected)`)
     })
 
+    log.info(`+ WebSocket connection (${remoteAddress}) (${connections.size} connected)`)
+
     return connection
   }
 
@@ -305,7 +308,7 @@ export default class Xo extends EventEmitter {
         return
       }
 
-      forEach(connections, connection => {
+      for (const connection of connections) {
         // Notifies only authenticated clients.
         if (connection.has('user_id') && connection.notify) {
           if (enteredMessage) {
@@ -315,7 +318,7 @@ export default class Xo extends EventEmitter {
             connection.notify('all', exitedMessage)
           }
         }
-      })
+      }
 
       reset()
     })