diff --git a/ldap-overleaf-sl/Dockerfile b/ldap-overleaf-sl/Dockerfile
index fec6ea2..0d702cd 100644
--- a/ldap-overleaf-sl/Dockerfile
+++ b/ldap-overleaf-sl/Dockerfile
@@ -36,7 +36,7 @@ COPY sharelatex/AuthenticationManager.js    /overleaf/services/web/app/src/Featu
 COPY sharelatex/AuthenticationController.js /overleaf/services/web/app/src/Features/Authentication/
 COPY sharelatex/ContactController.js        /overleaf/services/web/app/src/Features/Contacts/
 COPY sharelatex/ProjectEditorHandler.js     /overleaf/services/web/app/src/Features/Project/
-COPY sharelatex/TrackChangesController.js   /overleaf/services/web/app/src/Features/TrackChanges/
+COPY sharelatex_diff/TrackChangesController.js   /overleaf/services/web/app/src/Features/TrackChanges/
 COPY sharelatex/router.js                   /overleaf/services/web/app/src/router.js
 
 ## Copy some new files from the Docker git repo (because they are not in the current Docker release - to enable Track-Changes
diff --git a/ldap-overleaf-sl/sharelatex_diff/TrackChangesController.js b/ldap-overleaf-sl/sharelatex_diff/TrackChangesController.js
new file mode 100644
index 0000000..7151cb8
--- /dev/null
+++ b/ldap-overleaf-sl/sharelatex_diff/TrackChangesController.js
@@ -0,0 +1,308 @@
+const ChatApiHandler = require('../Chat/ChatApiHandler')
+const ChatManager = require('../Chat/ChatManager')
+const EditorRealTimeController = require('../Editor/EditorRealTimeController')
+const SessionManager = require('../Authentication/SessionManager')
+const UserInfoManager = require('../User/UserInfoManager')
+const DocstoreManager = require('../Docstore/DocstoreManager')
+const DocumentUpdaterHandler = require('../DocumentUpdater/DocumentUpdaterHandler')
+const CollaboratorsGetter = require('../Collaborators/CollaboratorsGetter')
+const { Project } = require('../../models/Project')
+const pLimit = require('p-limit')
+
+async function _updateTCState (projectId, state, callback) {
+  await Project.updateOne({_id: projectId}, {track_changes: state}).exec()
+  callback()
+}
+function _transformId(doc) {
+  if (doc._id) {
+    doc.id = doc._id;
+    delete doc._id;
+  }
+  return doc;
+}
+
+const TrackChangesController = {
+  trackChanges(req, res, next) {
+    const { project_id } = req.params
+    let state = req.body.on || req.body.on_for
+    if ( req.body.on_for_guests && !req.body.on ) state.__guests__ = true
+
+    return _updateTCState(project_id, state,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+        EditorRealTimeController.emitToRoom(
+          project_id,
+          'toggle-track-changes',
+          state
+        )
+        return res.sendStatus(204)
+      }
+    )
+  },
+  acceptChanges(req, res, next) {
+    const { project_id, doc_id } = req.params
+    const change_ids = req.body.change_ids
+    return DocumentUpdaterHandler.acceptChanges(
+      project_id,
+      doc_id,
+      change_ids,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+        EditorRealTimeController.emitToRoom(
+          project_id,
+          'accept-changes',
+          doc_id,
+          change_ids,
+        )
+        return res.sendStatus(204)
+      }
+    )
+  },
+  async getAllRanges(req, res, next) {
+    const { project_id } = req.params
+    // FIXME: ranges are from mongodb, probably already outdated
+    const ranges = await DocstoreManager.promises.getAllRanges(project_id)
+// frontend expects 'id', not '_id'
+    return res.json(ranges.map(_transformId))
+  },
+  async getChangesUsers(req, res, next) {
+    const { project_id } = req.params
+    const memberIds = await CollaboratorsGetter.promises.getMemberIds(project_id)
+    // FIXME: Does not work properly if the user is no longer a member of the project
+    // memberIds from DocstoreManager.getAllRanges(project_id) is not a remedy
+    // because ranges are not updated in real-time
+    const limit = pLimit(3)
+    const users = await Promise.all(
+      memberIds.map(memberId =>
+        limit(async () => {
+          const user = await UserInfoManager.promises.getPersonalInfo(memberId)
+          return user
+        })
+      )
+    )
+    users.push({_id: null}) // An anonymous user won't cause any harm
+// frontend expects 'id', not '_id'
+    return res.json(users.map(_transformId))
+  },
+  getThreads(req, res, next) {
+    const { project_id } = req.params
+    return ChatApiHandler.getThreads(
+      project_id,
+      function (err, messages) {
+        if (err != null) {
+          return next(err)
+        }
+        return ChatManager.injectUserInfoIntoThreads(
+          messages,
+          function (err) {
+            if (err != null) {
+              return next(err)
+            }
+            return res.json(messages)
+          }
+        )
+      }
+    )
+  },
+  sendComment(req, res, next) {
+    const { project_id, thread_id } = req.params
+    const { content } = req.body
+    const user_id = SessionManager.getLoggedInUserId(req.session)
+    if (user_id == null) {
+      const err = new Error('no logged-in user')
+      return next(err)
+    }
+    return ChatApiHandler.sendComment(
+      project_id,
+      thread_id,
+      user_id,
+      content,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+        return UserInfoManager.getPersonalInfo(
+          user_id,
+          function (err, user) {
+            if (err != null) {
+              return next(err)
+            }
+            message.user = user
+            EditorRealTimeController.emitToRoom(
+              project_id,
+              'new-comment',
+              thread_id, message
+            )
+            return res.sendStatus(204)
+          }
+        )
+      }
+    )
+  },
+  editMessage(req, res, next) {
+    const { project_id, thread_id, message_id } = req.params
+    const { content } = req.body
+    const user_id = SessionManager.getLoggedInUserId(req.session)
+    if (user_id == null) {
+      const err = new Error('no logged-in user')
+      return next(err)
+    }
+    return ChatApiHandler.editMessage(
+      project_id,
+      thread_id,
+      message_id,
+      user_id,
+      content,
+      function (err, message) {
+        if (err != null) {
+            return next(err)
+        }
+        EditorRealTimeController.emitToRoom(
+          project_id,
+          'edit-message',
+          thread_id,
+          message_id,
+          content
+        )
+        return res.sendStatus(204)
+      }
+    )
+  },
+  deleteMessage(req, res, next) {
+    const { project_id, thread_id, message_id } = req.params
+    return ChatApiHandler.deleteMessage(
+      project_id,
+      thread_id,
+      message_id,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+        EditorRealTimeController.emitToRoom(
+          project_id,
+          'delete-message',
+          thread_id,
+          message_id
+        )
+        return res.sendStatus(204)
+      }
+    )
+  },
+  resolveThread(req, res, next) {
+    const { project_id, doc_id, thread_id } = req.params
+    const user_id = SessionManager.getLoggedInUserId(req.session)
+    if (user_id == null) {
+      const err = new Error('no logged-in user')
+      return next(err)
+    }
+    DocumentUpdaterHandler.resolveThread(
+      project_id,
+      doc_id,
+      thread_id,
+      user_id,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+      }
+    )
+    return ChatApiHandler.resolveThread(
+      project_id,
+      thread_id,
+      user_id,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+        return UserInfoManager.getPersonalInfo(
+          user_id,
+          function (err, user) {
+            if (err != null) {
+              return next(err)
+            }
+            EditorRealTimeController.emitToRoom(
+              project_id,
+              'resolve-thread',
+              thread_id,
+              user_id
+            )
+            return res.sendStatus(204)
+          }
+        )
+      }
+    )
+  },
+  reopenThread(req, res, next) {
+    const { project_id, doc_id, thread_id } = req.params
+    const user_id = SessionManager.getLoggedInUserId(req.session)
+    if (user_id == null) {
+      const err = new Error('no logged-in user')
+      return next(err)
+    }
+    DocumentUpdaterHandler.reopenThread(
+      project_id,
+      doc_id,
+      thread_id,
+      user_id,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+      }
+    )
+    return ChatApiHandler.reopenThread(
+      project_id,
+      thread_id,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+        EditorRealTimeController.emitToRoom(
+          project_id,
+          'reopen-thread',
+          thread_id
+        )
+        return res.sendStatus(204)
+      }
+    )
+  },
+  deleteThread(req, res, next) {
+    const { project_id, doc_id, thread_id } = req.params
+    const user_id = SessionManager.getLoggedInUserId(req.session)
+    if (user_id == null) {
+      const err = new Error('no logged-in user')
+      return next(err)
+    }
+    return DocumentUpdaterHandler.deleteThread(
+      project_id,
+      doc_id,
+      thread_id,
+      user_id,
+      function (err, message) {
+        if (err != null) {
+          return next(err)
+        }
+        ChatApiHandler.deleteThread(
+          project_id,
+          thread_id,
+          function (err, message) {
+            if (err != null) {
+              return next(err)
+            }
+            EditorRealTimeController.emitToRoom(
+              project_id,
+              'delete-thread',
+              thread_id
+            )   
+            return res.sendStatus(204)
+          }
+        )
+      }
+    )
+  },
+}
+module.exports = TrackChangesController