diff --git a/lib/ot/editor-socketio-server.js b/lib/ot/editor-socketio-server.js
deleted file mode 100755
index 5014ac8d2..000000000
--- a/lib/ot/editor-socketio-server.js
+++ /dev/null
@@ -1,164 +0,0 @@
-'use strict';
-
-var EventEmitter = require('events').EventEmitter;
-var TextOperation = require('./text-operation');
-var WrappedOperation = require('./wrapped-operation');
-var Server = require('./server');
-var Selection = require('./selection');
-var util = require('util');
-
-var logger = require('../logger');
-
-function EditorSocketIOServer(document, operations, docId, mayWrite, operationCallback) {
-    EventEmitter.call(this);
-    Server.call(this, document, operations);
-    this.users = {};
-    this.docId = docId;
-    this.mayWrite = mayWrite || function (_, cb) {
-        cb(true);
-    };
-    this.operationCallback = operationCallback;
-}
-
-util.inherits(EditorSocketIOServer, Server);
-extend(EditorSocketIOServer.prototype, EventEmitter.prototype);
-
-function extend(target, source) {
-    for (var key in source) {
-        if (source.hasOwnProperty(key)) {
-            target[key] = source[key];
-        }
-    }
-}
-
-EditorSocketIOServer.prototype.addClient = function (socket) {
-    var self = this;
-    socket.join(this.docId);
-    var docOut = {
-        str: this.document,
-        revision: this.operations.length,
-        clients: this.users
-    };
-    socket.emit('doc', docOut);
-    socket.on('operation', function (revision, operation, selection) {
-        socket.origin = 'operation';
-        self.mayWrite(socket, function (mayWrite) {
-            if (!mayWrite) {
-                logger.info("User doesn't have the right to edit.");
-                return;
-            }
-            try {
-                self.onOperation(socket, revision, operation, selection);
-                if (typeof self.operationCallback === 'function')
-                    self.operationCallback(socket, operation);
-            } catch (err) {
-                setTimeout(function() {
-                    var docOut = {
-                        str: self.document,
-                        revision: self.operations.length,
-                        clients: self.users,
-                        force: true
-                    };
-                    socket.emit('doc', docOut);
-                }, 100);
-            }
-        });
-    });
-    socket.on('get_operations', function (base, head) {
-        self.onGetOperations(socket, base, head);
-    });
-    socket.on('selection', function (obj) {
-        socket.origin = 'selection';
-        self.mayWrite(socket, function (mayWrite) {
-            if (!mayWrite) {
-                logger.info("User doesn't have the right to edit.");
-                return;
-            }
-            self.updateSelection(socket, obj && Selection.fromJSON(obj));
-        });
-    });
-    socket.on('disconnect', function () {
-        logger.debug("Disconnect");
-        socket.leave(self.docId);
-        self.onDisconnect(socket);
-        /*
-        if (socket.manager && socket.manager.sockets.clients(self.docId).length === 0) {
-          self.emit('empty-room');
-        }
-        */
-    });
-};
-
-EditorSocketIOServer.prototype.onOperation = function (socket, revision, operation, selection) {
-    var wrapped;
-    try {
-        wrapped = new WrappedOperation(
-            TextOperation.fromJSON(operation),
-            selection && Selection.fromJSON(selection)
-        );
-    } catch (exc) {
-        logger.error("Invalid operation received: ");
-        logger.error(exc);
-        throw new Error(exc);
-    }
-
-    try {
-        var clientId = socket.id;
-        var wrappedPrime = this.receiveOperation(revision, wrapped);
-        if(!wrappedPrime) return;
-        logger.debug("new operation: " + JSON.stringify(wrapped));
-        this.getClient(clientId).selection = wrappedPrime.meta;
-        revision = this.operations.length;
-        socket.emit('ack', revision);
-        socket.broadcast.in(this.docId).emit(
-            'operation', clientId, revision,
-            wrappedPrime.wrapped.toJSON(), wrappedPrime.meta
-        );
-        //set document is dirty
-        this.isDirty = true;
-    } catch (exc) {
-        logger.error(exc);
-        throw new Error(exc);
-    }
-};
-
-EditorSocketIOServer.prototype.onGetOperations = function (socket, base, head) {
-    var operations = this.operations.slice(base, head).map(function (op) {
-        return op.wrapped.toJSON();
-    });
-    socket.emit('operations', head, operations);
-};
-
-EditorSocketIOServer.prototype.updateSelection = function (socket, selection) {
-    var clientId = socket.id;
-    if (selection) {
-        this.getClient(clientId).selection = selection;
-    } else {
-        delete this.getClient(clientId).selection;
-    }
-    socket.broadcast.to(this.docId).emit('selection', clientId, selection);
-};
-
-EditorSocketIOServer.prototype.setName = function (socket, name) {
-    var clientId = socket.id;
-    this.getClient(clientId).name = name;
-    socket.broadcast.to(this.docId).emit('set_name', clientId, name);
-};
-
-EditorSocketIOServer.prototype.setColor = function (socket, color) {
-    var clientId = socket.id;
-    this.getClient(clientId).color = color;
-    socket.broadcast.to(this.docId).emit('set_color', clientId, color);
-};
-
-EditorSocketIOServer.prototype.getClient = function (clientId) {
-    return this.users[clientId] || (this.users[clientId] = {});
-};
-
-EditorSocketIOServer.prototype.onDisconnect = function (socket) {
-    var clientId = socket.id;
-    delete this.users[clientId];
-    socket.broadcast.to(this.docId).emit('client_left', clientId);
-};
-
-module.exports = EditorSocketIOServer;
diff --git a/lib/ot/editor-socketio-server.ts b/lib/ot/editor-socketio-server.ts
new file mode 100755
index 000000000..cb27d7f04
--- /dev/null
+++ b/lib/ot/editor-socketio-server.ts
@@ -0,0 +1,155 @@
+import { EventEmitter } from 'events'
+import { logger } from '../logger'
+import Selection from './selection'
+import Server from './server'
+import TextOperation from './text-operation'
+import WrappedOperation from './wrapped-operation'
+
+export class EditorSocketIOServer extends Server {
+  private readonly users: {}
+  private readonly docId: any
+  private mayWrite: any
+
+  constructor (document, operations, docId, mayWrite, operationCallback) {
+    super(document, operations)
+    // Whatever that does?
+    EventEmitter.call(this)
+    this.users = {}
+    this.docId = docId
+    this.mayWrite = mayWrite || function (_, cb) {
+      cb(true)
+    }
+    this.operationCallback = operationCallback
+  }
+
+  addClient (socket) {
+    const self = this
+    socket.join(this.docId)
+    const docOut = {
+      str: this.document,
+      revision: this.operations.length,
+      clients: this.users
+    }
+    socket.emit('doc', docOut)
+    socket.on('operation', function (revision, operation, selection) {
+      socket.origin = 'operation'
+      self.mayWrite(socket, function (mayWrite) {
+        if (!mayWrite) {
+          logger.info("User doesn't have the right to edit.")
+          return
+        }
+        try {
+          self.onOperation(socket, revision, operation, selection)
+          if (typeof self.operationCallback === 'function')
+            self.operationCallback(socket, operation)
+        } catch (err) {
+          setTimeout(function () {
+            const docOut = {
+              str: self.document,
+              revision: self.operations.length,
+              clients: self.users,
+              force: true
+            }
+            socket.emit('doc', docOut)
+          }, 100)
+        }
+      })
+    })
+    socket.on('get_operations', function (base, head) {
+      self.onGetOperations(socket, base, head)
+    })
+    socket.on('selection', function (obj) {
+      socket.origin = 'selection'
+      self.mayWrite(socket, function (mayWrite) {
+        if (!mayWrite) {
+          logger.info("User doesn't have the right to edit.")
+          return
+        }
+        self.updateSelection(socket, obj && Selection.fromJSON(obj))
+      })
+    })
+    socket.on('disconnect', function () {
+      logger.debug("Disconnect")
+      socket.leave(self.docId)
+      self.onDisconnect(socket)
+      /*
+      if (socket.manager && socket.manager.sockets.clients(self.docId).length === 0) {
+        self.emit('empty-room');
+      }
+      */
+    })
+  };
+
+  onOperation (socket, revision, operation, selection) {
+    let wrapped
+    try {
+      wrapped = new WrappedOperation(
+        TextOperation.fromJSON(operation),
+        selection && Selection.fromJSON(selection)
+      )
+    } catch (exc) {
+      logger.error("Invalid operation received: ")
+      logger.error(exc)
+      throw new Error(exc)
+    }
+
+    try {
+      const clientId = socket.id
+      const wrappedPrime = this.receiveOperation(revision, wrapped)
+      if (!wrappedPrime) return
+      logger.debug("new operation: " + JSON.stringify(wrapped))
+      this.getClient(clientId).selection = wrappedPrime.meta
+      revision = this.operations.length
+      socket.emit('ack', revision)
+      socket.broadcast.in(this.docId).emit(
+        'operation', clientId, revision,
+        wrappedPrime.wrapped.toJSON(), wrappedPrime.meta
+      )
+      //set document is dirty
+      this.isDirty = true
+    } catch (exc) {
+      logger.error(exc)
+      throw new Error(exc)
+    }
+  };
+
+  onGetOperations (socket, base, head) {
+    const operations = this.operations.slice(base, head).map(function (op) {
+      return op.wrapped.toJSON()
+    })
+    socket.emit('operations', head, operations)
+  };
+
+  updateSelection (socket, selection) {
+    const clientId = socket.id
+    if (selection) {
+      this.getClient(clientId).selection = selection
+    } else {
+      delete this.getClient(clientId).selection
+    }
+    socket.broadcast.to(this.docId).emit('selection', clientId, selection)
+  };
+
+  setName (socket, name) {
+    const clientId = socket.id
+    this.getClient(clientId).name = name
+    socket.broadcast.to(this.docId).emit('set_name', clientId, name)
+  };
+
+  setColor (socket, color) {
+    const clientId = socket.id
+    this.getClient(clientId).color = color
+    socket.broadcast.to(this.docId).emit('set_color', clientId, color)
+  };
+
+  getClient (clientId) {
+    return this.users[clientId] || (this.users[clientId] = {})
+  };
+
+  onDisconnect (socket) {
+    const clientId = socket.id
+    delete this.users[clientId]
+    socket.broadcast.to(this.docId).emit('client_left', clientId)
+  };
+}
+
diff --git a/lib/realtime.ts b/lib/realtime.ts
index 1934c18ba..c6daaaaa6 100644
--- a/lib/realtime.ts
+++ b/lib/realtime.ts
@@ -10,6 +10,7 @@ import async from 'async'
 import cookieParser from 'cookie-parser'
 import cookie from 'cookie'
 import Chance from 'chance'
+import { EditorSocketIOServer } from './ot/editor-socketio-server'
 
 const chance = new Chance()
 
@@ -577,7 +578,7 @@ function startConnection (socket) {
       const body = note.content
       const createtime = note.createdAt
       const updatetime = note.lastchangeAt
-      const server = new ot.EditorSocketIOServer(body, [], noteId, ifMayEdit, operationCallback)
+      const server = new EditorSocketIOServer(body, [], noteId, ifMayEdit, operationCallback)
 
       const authors = {}
       for (let i = 0; i < note.authors.length; i++) {