diff --git a/History.md b/History.md
index 1491b8ce2b..bd0cbf4715 100644
--- a/History.md
+++ b/History.md
@@ -1,3 +1,8 @@
+0.9.19-overleaf-10 / 2023-04-25
+===============================
+
+* Overleaf: Add support for Node 18 by gracefully handling `req.socket == null`.
+
 0.9.19-overleaf-9 / 2022-08-18
 ==============================
 
diff --git a/lib/manager.js b/lib/manager.js
index d3ccf1a842..95dc9b5e38 100644
--- a/lib/manager.js
+++ b/lib/manager.js
@@ -115,7 +115,21 @@ function Manager (server, options) {
   server.removeAllListeners('request');
 
   server.on('request', function (req, res) {
-    self.handleRequest(req, res);
+    var socket = req.socket;
+    if (!socket) {
+      // aborted request
+      self.log.warn('bail out from aborted request (req.socket missing)');
+      // nginx uses status code 499 when clients close the connection before a response could be sent.
+      // https://github.com/nginx/nginx/blob/bfc5b35827903a3c543b58e4562db8b62021c164/src/http/ngx_http_request.h#L128-L134
+      try {
+        res.writeHead(499);
+        res.end();
+      } catch (e) {
+        self.log.warn('cannot reply to aborted request: ' + e.message);
+      }
+      return;
+    }
+    self.handleRequest(req, res, socket);
   });
 
   server.on('upgrade', function (req, socket, head) {
@@ -579,7 +593,7 @@ Manager.prototype.onDisconnect = function (id) {
  * @api private
  */
 
-Manager.prototype.handleRequest = function (req, res) {
+Manager.prototype.handleRequest = function (req, res, socket) {
   var data = this.checkRequest(req);
 
   if (!data) {
@@ -610,9 +624,9 @@ Manager.prototype.handleRequest = function (req, res) {
     this.log.info('client protocol version unsupported');
   } else {
     if (data.id) {
-      this.handleHTTPRequest(data, req, res);
+      this.handleHTTPRequest(data, req, res, socket);
     } else {
-      this.handleHandshake(data, req, res);
+      this.handleHandshake(data, req, res, socket);
     }
   }
 };
@@ -637,7 +651,7 @@ Manager.prototype.handleUpgrade = function (req, socket, head) {
   }
 
   req.head = head;
-  this.handleClient(data, req);
+  this.handleClient(data, req, socket);
   req.head = null;
 };
 
@@ -647,9 +661,9 @@ Manager.prototype.handleUpgrade = function (req, socket, head) {
  * @api private
  */
 
-Manager.prototype.handleHTTPRequest = function (data, req, res) {
+Manager.prototype.handleHTTPRequest = function (data, req, res, socket) {
   req.res = res;
-  this.handleClient(data, req);
+  this.handleClient(data, req, socket);
 };
 
 /**
@@ -658,11 +672,7 @@ Manager.prototype.handleHTTPRequest = function (data, req, res) {
  * @api private
  */
 
-Manager.prototype.handleClient = function (data, req) {
-  var socket = req.socket
-    , store = this.store
-    , self = this;
-
+Manager.prototype.handleClient = function (data, req, socket) {
   // handle sync disconnect xhrs
   if (undefined != data.query.disconnect) {
     if (this.transports[data.id] && this.transports[data.id].open) {
@@ -677,16 +687,16 @@ Manager.prototype.handleClient = function (data, req) {
 
   if (!~this.get('transports').indexOf(data.transport)) {
     this.log.warn('unknown transport: "' + data.transport + '"');
-    req.connection.end();
+    socket.end();
     return;
   }
 
-  var transport = new transports[data.transport](this, data, req)
+  var transport = new transports[data.transport](this, data, req, socket)
     , handshaken = this.handshaken[data.id];
 
   if (transport.disconnected) {
     // failed during transport setup
-    req.connection.end();
+    socket.end();
     return;
   }
   if (handshaken) {
@@ -713,7 +723,7 @@ Manager.prototype.handleClient = function (data, req) {
       // initialize the socket for all namespaces
       for (var i in this.namespaces) {
         if (this.namespaces.hasOwnProperty(i)) {
-          var socket = this.namespaces[i].socket(data.id, true);
+          this.namespaces[i].socket(data.id, true);
 
           // echo back connect packet and fire connection event
           if (i === '') {
@@ -762,7 +772,7 @@ Manager.prototype.generateId = function () {
  * @api private
  */
 
-Manager.prototype.handleHandshake = function (data, req, res) {
+Manager.prototype.handleHandshake = function (data, req, res, socket) {
   var self = this
     , origin = req.headers.origin
     , headers = {
@@ -789,7 +799,7 @@ Manager.prototype.handleHandshake = function (data, req, res) {
     return;
   }
 
-  var handshakeData = this.handshakeData(data);
+  var handshakeData = this.handshakeData(data, socket);
 
   if (origin) {
     // https://developer.mozilla.org/En/HTTP_Access_Control
@@ -835,9 +845,8 @@ Manager.prototype.handleHandshake = function (data, req, res) {
  * @api private
  */
 
-Manager.prototype.handshakeData = function (data) {
-  var connection = data.request.connection
-    , connectionAddress
+Manager.prototype.handshakeData = function (data, connection) {
+  var connectionAddress
     , date = new Date;
 
   if (connection.remoteAddress) {
@@ -859,7 +868,7 @@ Manager.prototype.handshakeData = function (data) {
     , query: data.query
     , url: data.request.url
     , xdomain: !!data.request.headers.origin
-    , secure: data.request.connection.secure
+    , secure: connection.secure
     , issued: +date
   };
 };
diff --git a/lib/socket.io.js b/lib/socket.io.js
index 0016ebf27c..bee950f2ac 100644
--- a/lib/socket.io.js
+++ b/lib/socket.io.js
@@ -16,7 +16,7 @@
  * Version.
  */
 
-exports.version = '0.9.19-overleaf-4';
+exports.version = '0.9.19-overleaf-10';
 
 /**
  * Supported protocol version.
diff --git a/lib/transport.js b/lib/transport.js
index e04d2aee2d..79a1851828 100644
--- a/lib/transport.js
+++ b/lib/transport.js
@@ -23,12 +23,12 @@ exports = module.exports = Transport;
  * @api public
  */
 
-function Transport (mng, data, req) {
+function Transport (mng, data, req, socket) {
   this.manager = mng;
   this.id = data.id;
   this.disconnected = false;
   this.drained = true;
-  this.handleRequest(req);
+  this.handleRequest(req, socket);
 };
 
 /**
@@ -57,12 +57,12 @@ Transport.prototype.__defineGetter__('store', function () {
  * @api private
  */
 
-Transport.prototype.handleRequest = function (req) {
+Transport.prototype.handleRequest = function (req, socket) {
   this.log.debug('setting request', req.method, req.url);
   this.req = req;
 
   if (req.method == 'GET') {
-    this.socket = req.socket;
+    this.socket = socket;
     this.open = true;
     this.drained = true;
     this.setHeartbeatInterval();
diff --git a/lib/transports/flashsocket.js b/lib/transports/flashsocket.js
index 35daa85e39..21b9aa2c80 100644
--- a/lib/transports/flashsocket.js
+++ b/lib/transports/flashsocket.js
@@ -42,8 +42,8 @@ exports = module.exports = FlashSocket;
  * @api public
  */
  
-function FlashSocket (mng, data, req) {
-  return WebSocket.call(this, mng, data, req);
+function FlashSocket (mng, data, req, socket) {
+  return WebSocket.call(this, mng, data, req, socket);
 }
 
 /**
diff --git a/lib/transports/htmlfile.js b/lib/transports/htmlfile.js
index fce0c0ed56..6efeb732db 100644
--- a/lib/transports/htmlfile.js
+++ b/lib/transports/htmlfile.js
@@ -23,8 +23,8 @@ exports = module.exports = HTMLFile;
  * @api public
  */
 
-function HTMLFile (mng, data, req) {
-  HTTPTransport.call(this, mng, data, req);
+function HTMLFile (mng, data, req, socket) {
+  HTTPTransport.call(this, mng, data, req, socket);
 };
 
 /**
@@ -47,8 +47,8 @@ HTMLFile.prototype.name = 'htmlfile';
  * @api private
  */
 
-HTMLFile.prototype.handleRequest = function (req) {
-  HTTPTransport.prototype.handleRequest.call(this, req);
+HTMLFile.prototype.handleRequest = function (req, socket) {
+  HTTPTransport.prototype.handleRequest.call(this, req, socket);
 
   if (req.method == 'GET') {
     req.res.writeHead(200, {
diff --git a/lib/transports/http-polling.js b/lib/transports/http-polling.js
index 89b7e0428b..cd4b673b72 100644
--- a/lib/transports/http-polling.js
+++ b/lib/transports/http-polling.js
@@ -23,8 +23,8 @@ exports = module.exports = HTTPPolling;
  * @api public.
  */
 
-function HTTPPolling (mng, data, req) {
-  HTTPTransport.call(this, mng, data, req);
+function HTTPPolling (mng, data, req, socket) {
+  HTTPTransport.call(this, mng, data, req, socket);
 };
 
 /**
@@ -69,8 +69,8 @@ HTTPPolling.prototype.setHeartbeatInterval = function () {
  * @api private
  */
 
-HTTPPolling.prototype.handleRequest = function (req) {
-  HTTPTransport.prototype.handleRequest.call(this, req);
+HTTPPolling.prototype.handleRequest = function (req, socket) {
+  HTTPTransport.prototype.handleRequest.call(this, req, socket);
 
   if (req.method == 'GET') {
     var self = this;
diff --git a/lib/transports/http.js b/lib/transports/http.js
index fa94b5975f..dc17668b26 100644
--- a/lib/transports/http.js
+++ b/lib/transports/http.js
@@ -25,8 +25,8 @@ exports = module.exports = HTTPTransport;
  * @api public
  */
 
-function HTTPTransport (mng, data, req) {
-  Transport.call(this, mng, data, req);
+function HTTPTransport (mng, data, req, socket) {
+  Transport.call(this, mng, data, req, socket);
 };
 
 /**
@@ -41,7 +41,7 @@ HTTPTransport.prototype.__proto__ = Transport.prototype;
  * @api private
  */
 
-HTTPTransport.prototype.handleRequest = function (req) {
+HTTPTransport.prototype.handleRequest = function (req, socket) {
 
   // Always set the response in case an error is returned to the client
   this.response = req.res;
@@ -58,7 +58,11 @@ HTTPTransport.prototype.handleRequest = function (req) {
 
       if (Buffer.byteLength(buffer) >= self.manager.get('destroy buffer size')) {
         buffer = '';
-        req.connection.destroy();
+        if (socket.destroy) {
+          socket.destroy();
+        } else if (socket.end) {
+          socket.end();
+        }
       }
     });
 
@@ -82,7 +86,7 @@ HTTPTransport.prototype.handleRequest = function (req) {
       headers['X-XSS-Protection'] = '0';
     }
   } else {
-    Transport.prototype.handleRequest.call(this, req);
+    Transport.prototype.handleRequest.call(this, req, socket);
   }
 };
 
diff --git a/lib/transports/jsonp-polling.js b/lib/transports/jsonp-polling.js
index ad7d5aff3c..2d01eb1c87 100644
--- a/lib/transports/jsonp-polling.js
+++ b/lib/transports/jsonp-polling.js
@@ -24,8 +24,8 @@ exports = module.exports = JSONPPolling;
  * @api public
  */
 
-function JSONPPolling (mng, data, req) {
-  HTTPPolling.call(this, mng, data, req);
+function JSONPPolling (mng, data, req, socket) {
+  HTTPPolling.call(this, mng, data, req, socket);
 
   this.head = 'io.j[0](';
   this.foot = ');';
diff --git a/lib/transports/websocket.js b/lib/transports/websocket.js
index 78a43043d5..fb3606ccd1 100644
--- a/lib/transports/websocket.js
+++ b/lib/transports/websocket.js
@@ -24,13 +24,13 @@ exports = module.exports = WebSocket;
  * @api public
  */
 
-function WebSocket (mng, data, req) {
+function WebSocket (mng, data, req, socket) {
   var transport
     , version = req.headers['sec-websocket-version'];
   if (typeof version !== 'undefined' && typeof protocolVersions[version] !== 'undefined') {
-    transport = new protocolVersions[version](mng, data, req);
+    transport = new protocolVersions[version](mng, data, req, socket);
   }
-  else transport = new protocolVersions['default'](mng, data, req);
+  else transport = new protocolVersions['default'](mng, data, req, socket);
   if (typeof this.name !== 'undefined') transport.name = this.name;
   return transport;
 };
diff --git a/lib/transports/websocket/default.js b/lib/transports/websocket/default.js
index 4ddb5f6c13..84b78eef1d 100644
--- a/lib/transports/websocket/default.js
+++ b/lib/transports/websocket/default.js
@@ -26,7 +26,7 @@ exports = module.exports = WebSocket;
  * @api public
  */
 
-function WebSocket (mng, data, req) {
+function WebSocket (mng, data, req, socket) {
   // parser
   var self = this;
 
@@ -47,7 +47,7 @@ function WebSocket (mng, data, req) {
     self.end();
   });
 
-  Transport.call(this, mng, data, req);
+  Transport.call(this, mng, data, req, socket);
 };
 
 /**
diff --git a/lib/transports/websocket/hybi-07-12.js b/lib/transports/websocket/hybi-07-12.js
index 7bff6ff344..fcc2d24615 100644
--- a/lib/transports/websocket/hybi-07-12.js
+++ b/lib/transports/websocket/hybi-07-12.js
@@ -30,7 +30,7 @@ exports.Parser = Parser;
  * @api public
  */
 
-function WebSocket (mng, data, req) {
+function WebSocket (mng, data, req, socket) {
   // parser
   var self = this;
 
@@ -62,7 +62,7 @@ function WebSocket (mng, data, req) {
     self.end();
   });
 
-  Transport.call(this, mng, data, req);
+  Transport.call(this, mng, data, req, socket);
 };
 
 /**
diff --git a/lib/transports/websocket/hybi-16.js b/lib/transports/websocket/hybi-16.js
index e572bc40cb..1dfb6d0988 100644
--- a/lib/transports/websocket/hybi-16.js
+++ b/lib/transports/websocket/hybi-16.js
@@ -29,7 +29,7 @@ exports.Parser = Parser;
  * @api public
  */
 
-function WebSocket (mng, data, req) {
+function WebSocket (mng, data, req, socket) {
   // parser
   var self = this;
 
@@ -61,7 +61,7 @@ function WebSocket (mng, data, req) {
     self.end();
   });
 
-  Transport.call(this, mng, data, req);
+  Transport.call(this, mng, data, req, socket);
 };
 
 /**
diff --git a/lib/transports/xhr-polling.js b/lib/transports/xhr-polling.js
index 1db5aeee0f..3c9a7cb5f2 100644
--- a/lib/transports/xhr-polling.js
+++ b/lib/transports/xhr-polling.js
@@ -23,8 +23,8 @@ exports = module.exports = XHRPolling;
  * @api public
  */
 
-function XHRPolling (mng, data, req) {
-  HTTPPolling.call(this, mng, data, req);
+function XHRPolling (mng, data, req, socket) {
+  HTTPPolling.call(this, mng, data, req, socket);
 };
 
 /**
diff --git a/package.json b/package.json
index 819bf101b7..cc884209ca 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "socket.io"
-  , "version": "0.9.19-overleaf-9"
+  , "version": "0.9.19-overleaf-10"
   , "description": "Real-time apps made cross-browser & easy with a WebSocket-like API"
   , "homepage": "http://socket.io"
   , "keywords": ["websocket", "socket", "realtime", "socket.io", "comet", "ajax"]
diff --git a/support/node-websocket-client/lib/websocket.js b/support/node-websocket-client/lib/websocket.js
index 4f7f73425c..33910b38b0 100644
--- a/support/node-websocket-client/lib/websocket.js
+++ b/support/node-websocket-client/lib/websocket.js
@@ -506,7 +506,7 @@ var WebSocket = function(url, proto, opts) {
             var data = undefined;
 
             return function(req, s, head) {
-                req.socket.setNoDelay(true);
+                if (req.socket) req.socket.setNoDelay(true);
                 stream = s;
 
                 if (readyState == CLOSED) {