diff --git a/package-lock.json b/package-lock.json
index ba453cb422..f6875ab878 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -58898,6 +58898,7 @@
     "services/real-time": {
       "name": "@overleaf/real-time",
       "dependencies": {
+        "@overleaf/fetch-utils": "*",
         "@overleaf/logger": "*",
         "@overleaf/metrics": "*",
         "@overleaf/o-error": "*",
@@ -58920,7 +58921,6 @@
         "zod-validation-error": "^4.0.1"
       },
       "devDependencies": {
-        "@overleaf/fetch-utils": "*",
         "chai": "^4.3.6",
         "chai-as-promised": "^7.1.1",
         "cookie-signature": "^1.1.0",
diff --git a/services/real-time/app/js/DocumentUpdaterManager.js b/services/real-time/app/js/DocumentUpdaterManager.js
index 006777395c..36e21f385c 100644
--- a/services/real-time/app/js/DocumentUpdaterManager.js
+++ b/services/real-time/app/js/DocumentUpdaterManager.js
@@ -1,4 +1,3 @@
-import request from 'request'
 import _ from 'lodash'
 import OError from '@overleaf/o-error'
 import logger from '@overleaf/logger'
@@ -6,6 +5,12 @@ import settings from '@overleaf/settings'
 import metrics from '@overleaf/metrics'
 import RedisWrapper from '@overleaf/redis-wrapper'
 import Errors from './Errors.js'
+import {
+  fetchJson,
+  fetchNothing,
+  RequestFailedError,
+} from '@overleaf/fetch-utils'
+import { callbackify } from 'node:util'
 
 const {
   ClientRequestedMissingOpsError,
@@ -13,145 +18,141 @@ const {
   NullBytesInOpError,
   UpdateTooLargeError,
 } = Errors
+
 const rclient = RedisWrapper.createClient(settings.redis.documentupdater)
 const Keys = settings.redis.documentupdater.key_schema
 
-const DocumentUpdaterManager = {
-  getDocument(projectId, docId, fromVersion, callback) {
-    const timer = new metrics.Timer('get-document')
-    const url = `${settings.apis.documentupdater.url}/project/${projectId}/doc/${docId}?fromVersion=${fromVersion}&historyOTSupport=true`
-    logger.debug(
-      { projectId, docId, fromVersion },
-      'getting doc from document updater'
-    )
-    request.get(url, function (err, res, body) {
-      timer.done()
-      if (err) {
-        OError.tag(err, 'error getting doc from doc updater')
-        return callback(err)
+async function getDocument(projectId, docId, fromVersion) {
+  const timer = new metrics.Timer('get-document')
+  const url = `${settings.apis.documentupdater.url}/project/${projectId}/doc/${docId}?fromVersion=${fromVersion}&historyOTSupport=true`
+  logger.debug(
+    { projectId, docId, fromVersion },
+    'getting doc from document updater'
+  )
+  try {
+    const body = await fetchJson(url)
+    timer.done()
+    logger.debug({ projectId, docId }, 'got doc from document document updater')
+    return {
+      lines: body?.lines,
+      version: body?.version,
+      ranges: body?.ranges,
+      ops: body?.ops,
+      ttlInS: body?.ttlInS,
+      type: body?.type,
+    }
+  } catch (err) {
+    timer.done()
+    if (err instanceof RequestFailedError) {
+      const { response, body } = err
+      let parsedErrBody = null
+      try {
+        parsedErrBody = JSON.parse(body)
+      } catch (error) {
+        // ignore parse error
       }
-      if (res.statusCode >= 200 && res.statusCode < 300) {
-        logger.debug(
-          { projectId, docId },
-          'got doc from document document updater'
-        )
-        try {
-          body = JSON.parse(body)
-        } catch (error) {
-          OError.tag(error, 'error parsing doc updater response')
-          return callback(error)
-        }
-        body = body || {}
-        callback(
-          null,
-          body.lines,
-          body.version,
-          body.ranges,
-          body.ops,
-          body.ttlInS,
-          body.type
-        )
-      } else if (res.statusCode === 422 && body?.firstVersionInRedis) {
-        callback(new ClientRequestedMissingOpsError(422, body))
-      } else if ([404, 422].includes(res.statusCode)) {
-        callback(new ClientRequestedMissingOpsError(res.statusCode))
+      if (response.status === 422 && parsedErrBody?.firstVersionInRedis) {
+        throw new ClientRequestedMissingOpsError(422, parsedErrBody)
+      } else if ([404, 422].includes(response.status)) {
+        throw new ClientRequestedMissingOpsError(response.status)
       } else {
-        callback(
-          new DocumentUpdaterRequestFailedError('getDocument', res.statusCode)
+        throw new DocumentUpdaterRequestFailedError(
+          'getDocument',
+          response.status
         )
       }
-    })
-  },
-
-  checkDocument(projectId, docId, callback) {
-    // in this call fromVersion = -1 means get document without docOps
-    DocumentUpdaterManager.getDocument(projectId, docId, -1, callback)
-  },
-
-  flushProjectToMongoAndDelete(projectId, callback) {
-    // this method is called when the last connected user leaves the project
-    logger.debug({ projectId }, 'deleting project from document updater')
-    const timer = new metrics.Timer('delete.mongo.project')
-    // flush the project in the background when all users have left
-    const url =
-      `${settings.apis.documentupdater.url}/project/${projectId}?background=true` +
-      (settings.shutDownInProgress ? '&shutdown=true' : '')
-    request.del(url, function (err, res) {
-      timer.done()
-      if (err) {
-        OError.tag(err, 'error deleting project from document updater')
-        callback(err)
-      } else if (res.statusCode >= 200 && res.statusCode < 300) {
-        logger.debug({ projectId }, 'deleted project from document updater')
-        callback(null)
-      } else {
-        callback(
-          new DocumentUpdaterRequestFailedError(
-            'flushProjectToMongoAndDelete',
-            res.statusCode
-          )
-        )
-      }
-    })
-  },
-
-  _getPendingUpdateListKey() {
-    const shard = _.random(0, settings.pendingUpdateListShardCount - 1)
-    if (shard === 0) {
-      return 'pending-updates-list'
-    } else {
-      return `pending-updates-list-${shard}`
     }
-  },
-
-  queueChange(projectId, docId, change, callback) {
-    const allowedKeys = [
-      'doc',
-      'op',
-      'v',
-      'dupIfSource',
-      'meta',
-      'lastV',
-      'hash',
-    ]
-    change = _.pick(change, allowedKeys)
-    const jsonChange = JSON.stringify(change)
-    if (jsonChange.indexOf('\u0000') !== -1) {
-      // memory corruption check
-      return callback(new NullBytesInOpError(jsonChange))
-    }
-
-    const updateSize = jsonChange.length
-    if (updateSize > settings.maxUpdateSize) {
-      return callback(new UpdateTooLargeError(updateSize))
-    }
-
-    // record metric for each update added to queue
-    metrics.summary('redis.pendingUpdates', updateSize, { status: 'push' })
-
-    const docKey = `${projectId}:${docId}`
-    // Push onto pendingUpdates for doc_id first, because once the doc updater
-    // gets an entry on pending-updates-list, it starts processing.
-    rclient.rpush(
-      Keys.pendingUpdates({ doc_id: docId }),
-      jsonChange,
-      function (error) {
-        if (error) {
-          error = new OError('error pushing update into redis').withCause(error)
-          return callback(error)
-        }
-        const queueKey = DocumentUpdaterManager._getPendingUpdateListKey()
-        rclient.rpush(queueKey, docKey, function (error) {
-          if (error) {
-            error = new OError('error pushing doc_id into redis')
-              .withInfo({ queueKey })
-              .withCause(error)
-          }
-          callback(error)
-        })
-      }
-    )
-  },
+    OError.tag(err, 'error getting doc from doc updater')
+    throw err
+  }
 }
 
-export default DocumentUpdaterManager
+async function checkDocument(projectId, docId) {
+  // in this call fromVersion = -1 means get document without docOps
+  return await getDocument(projectId, docId, -1)
+}
+
+async function flushProjectToMongoAndDelete(projectId) {
+  // this method is called when the last connected user leaves the project
+  logger.debug({ projectId }, 'deleting project from document updater')
+  const timer = new metrics.Timer('delete.mongo.project')
+  // flush the project in the background when all users have left
+  const url =
+    `${settings.apis.documentupdater.url}/project/${projectId}?background=true` +
+    (settings.shutDownInProgress ? '&shutdown=true' : '')
+
+  try {
+    await fetchNothing(url, { method: 'DELETE' })
+    logger.debug({ projectId }, 'deleted project from document updater')
+    timer.done()
+  } catch (err) {
+    timer.done()
+    if (err instanceof RequestFailedError) {
+      throw new DocumentUpdaterRequestFailedError(
+        'flushProjectToMongoAndDelete',
+        err.response.status
+      )
+    }
+    OError.tag(err, 'error deleting project from document updater')
+    throw err
+  }
+}
+
+function _getPendingUpdateListKey() {
+  const shard = _.random(0, settings.pendingUpdateListShardCount - 1)
+  if (shard === 0) {
+    return 'pending-updates-list'
+  } else {
+    return `pending-updates-list-${shard}`
+  }
+}
+
+async function queueChange(projectId, docId, change) {
+  const allowedKeys = ['doc', 'op', 'v', 'dupIfSource', 'meta', 'lastV', 'hash']
+  change = _.pick(change, allowedKeys)
+  const jsonChange = JSON.stringify(change)
+  if (jsonChange.indexOf('\u0000') !== -1) {
+    // memory corruption check
+    throw new NullBytesInOpError(jsonChange)
+  }
+
+  const updateSize = jsonChange.length
+  if (updateSize > settings.maxUpdateSize) {
+    throw new UpdateTooLargeError(updateSize)
+  }
+
+  // record metric for each update added to queue
+  metrics.summary('redis.pendingUpdates', updateSize, { status: 'push' })
+
+  const docKey = `${projectId}:${docId}`
+  // Push onto pendingUpdates for doc_id first, because once the doc updater
+  // gets an entry on pending-updates-list, it starts processing.
+  try {
+    await rclient.rpush(Keys.pendingUpdates({ doc_id: docId }), jsonChange)
+  } catch (error) {
+    throw new OError('error pushing update into redis').withCause(error)
+  }
+
+  const queueKey = _getPendingUpdateListKey()
+  try {
+    await rclient.rpush(queueKey, docKey)
+  } catch (error) {
+    throw new OError('error pushing doc_id into redis')
+      .withInfo({ queueKey })
+      .withCause(error)
+  }
+}
+
+export default {
+  getDocument: callbackify(getDocument),
+  checkDocument: callbackify(checkDocument),
+  flushProjectToMongoAndDelete: callbackify(flushProjectToMongoAndDelete),
+  _getPendingUpdateListKey,
+  queueChange: callbackify(queueChange),
+  promises: {
+    getDocument,
+    checkDocument,
+    flushProjectToMongoAndDelete,
+    queueChange,
+  },
+}
diff --git a/services/real-time/app/js/WebsocketController.js b/services/real-time/app/js/WebsocketController.js
index 3c963f233e..c0b5faf669 100644
--- a/services/real-time/app/js/WebsocketController.js
+++ b/services/real-time/app/js/WebsocketController.js
@@ -287,7 +287,7 @@ export default WebsocketController = {
             projectId,
             docId,
             fromVersion,
-            function (error, lines, version, ranges, ops, ttlInS, type) {
+            function (error, { lines, version, ranges, ops, ttlInS, type }) {
               if (error) {
                 if (error instanceof ClientRequestedMissingOpsError) {
                   emitJoinDocCatchUpMetrics('missing', error.info)
diff --git a/services/real-time/package.json b/services/real-time/package.json
index c1ed730a8b..d89f49f4b9 100644
--- a/services/real-time/package.json
+++ b/services/real-time/package.json
@@ -18,6 +18,7 @@
     "types:check": "tsc --noEmit"
   },
   "dependencies": {
+    "@overleaf/fetch-utils": "*",
     "@overleaf/logger": "*",
     "@overleaf/metrics": "*",
     "@overleaf/o-error": "*",
@@ -40,7 +41,6 @@
     "zod-validation-error": "^4.0.1"
   },
   "devDependencies": {
-    "@overleaf/fetch-utils": "*",
     "chai": "^4.3.6",
     "chai-as-promised": "^7.1.1",
     "cookie-signature": "^1.1.0",
diff --git a/services/real-time/test/unit/js/DocumentUpdaterManager.test.js b/services/real-time/test/unit/js/DocumentUpdaterManager.test.js
index 7d28d4eb06..b35642b97a 100644
--- a/services/real-time/test/unit/js/DocumentUpdaterManager.test.js
+++ b/services/real-time/test/unit/js/DocumentUpdaterManager.test.js
@@ -6,7 +6,7 @@
  * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
  */
 import sinon from 'sinon'
-import { vi, describe, beforeEach, it, afterEach } from 'vitest'
+import { expect, vi, describe, beforeEach, it, afterEach } from 'vitest'
 import _ from 'lodash'
 const modulePath = '../../../app/js/DocumentUpdaterManager'
 
@@ -31,13 +31,26 @@ describe('DocumentUpdaterManager', function () {
       pendingUpdateListShardCount: 10,
     }
     ctx.rclient = { auth() {} }
+    ctx.fetchJson = sinon.stub()
+    ctx.fetchNothing = sinon.stub()
+    ctx.RequestFailedError = class RequestFailedError extends Error {
+      constructor(message, url, options, response, body) {
+        super(message)
+        this.url = url
+        this.options = options
+        this.response = response
+        this.body = body
+      }
+    }
 
     vi.doMock('@overleaf/settings', () => ({
       default: ctx.settings,
     }))
 
-    vi.doMock('request', () => ({
-      default: (ctx.request = {}),
+    vi.doMock('@overleaf/fetch-utils', () => ({
+      fetchJson: ctx.fetchJson,
+      fetchNothing: ctx.fetchNothing,
+      RequestFailedError: ctx.RequestFailedError,
     }))
 
     vi.doMock('@overleaf/redis-wrapper', () => ({
@@ -59,88 +72,75 @@ describe('DocumentUpdaterManager', function () {
   }) // avoid modifying JSON object directly
 
   describe('getDocument', function () {
-    beforeEach(function (ctx) {
-      ctx.callback = sinon.stub()
-    })
-
     describe('successfully', function () {
-      beforeEach(function (ctx) {
-        ctx.body = JSON.stringify({
+      beforeEach(async function (ctx) {
+        ctx.body = {
           lines: ctx.lines,
           version: ctx.version,
           ops: (ctx.ops = ['mock-op-1', 'mock-op-2']),
           ranges: (ctx.ranges = { mock: 'ranges' }),
-        })
+        }
         ctx.fromVersion = 2
-        ctx.request.get = sinon
-          .stub()
-          .callsArgWith(1, null, { statusCode: 200 }, ctx.body)
-        ctx.DocumentUpdaterManager.getDocument(
+        ctx.fetchJson.resolves(ctx.body)
+        ctx.result = await ctx.DocumentUpdaterManager.promises.getDocument(
           ctx.project_id,
           ctx.doc_id,
-          ctx.fromVersion,
-          ctx.callback
+          ctx.fromVersion
         )
       })
 
       it('should get the document from the document updater', function (ctx) {
         const url = `${ctx.settings.apis.documentupdater.url}/project/${ctx.project_id}/doc/${ctx.doc_id}?fromVersion=${ctx.fromVersion}&historyOTSupport=true`
-        ctx.request.get.calledWith(url).should.equal(true)
+        ctx.fetchJson.calledWith(url).should.equal(true)
       })
 
-      it('should call the callback with the lines, version, ranges and ops', function (ctx) {
-        ctx.callback
-          .calledWith(null, ctx.lines, ctx.version, ctx.ranges, ctx.ops)
-          .should.equal(true)
+      it('should return the lines, version, ranges and ops', function (ctx) {
+        ctx.result.lines.should.deep.equal(ctx.lines)
+        ctx.result.version.should.equal(ctx.version)
+        ctx.result.ranges.should.deep.equal(ctx.ranges)
+        ctx.result.ops.should.deep.equal(ctx.ops)
       })
     })
 
     describe('when the document updater API returns an error', function () {
       beforeEach(function (ctx) {
-        ctx.request.get = sinon
-          .stub()
-          .callsArgWith(
-            1,
-            (ctx.error = new Error('something went wrong')),
-            null,
-            null
-          )
-        ctx.DocumentUpdaterManager.getDocument(
-          ctx.project_id,
-          ctx.doc_id,
-          ctx.fromVersion,
-          ctx.callback
-        )
+        ctx.error = new Error('something went wrong')
+        ctx.fetchJson.rejects(ctx.error)
       })
 
-      it('should return an error to the callback', function (ctx) {
-        ctx.callback.calledWith(ctx.error).should.equal(true)
+      it('should throw an error', async function (ctx) {
+        await expect(
+          ctx.DocumentUpdaterManager.promises.getDocument(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.fromVersion
+          )
+        ).to.be.rejectedWith(ctx.error)
       })
     })
     ;[404, 422].forEach(statusCode =>
       describe(`when the document updater returns a ${statusCode} status code`, function () {
         beforeEach(function (ctx) {
-          ctx.request.get = sinon
-            .stub()
-            .callsArgWith(1, null, { statusCode }, '')
-          ctx.DocumentUpdaterManager.getDocument(
-            ctx.project_id,
-            ctx.doc_id,
-            ctx.fromVersion,
-            ctx.callback
+          const error = new ctx.RequestFailedError(
+            'error',
+            'url',
+            {},
+            { status: statusCode },
+            null
           )
+          ctx.fetchJson.rejects(error)
         })
 
-        it('should return the callback with an error', function (ctx) {
-          ctx.callback.called.should.equal(true)
-          ctx.callback
-            .calledWith(
-              sinon.match({
-                message: 'doc updater could not load requested ops',
-                info: { statusCode },
-              })
+        it('should throw an error with the status code', async function (ctx) {
+          const error = await expect(
+            ctx.DocumentUpdaterManager.promises.getDocument(
+              ctx.project_id,
+              ctx.doc_id,
+              ctx.fromVersion
             )
-            .should.equal(true)
+          ).to.be.rejected
+          error.message.should.equal('doc updater could not load requested ops')
+          error.info.statusCode.should.equal(statusCode)
           ctx.logger.error.called.should.equal(false)
           ctx.logger.warn.called.should.equal(false)
         })
@@ -149,106 +149,89 @@ describe('DocumentUpdaterManager', function () {
 
     describe('when the document updater returns a failure error code', function () {
       beforeEach(function (ctx) {
-        ctx.request.get = sinon
-          .stub()
-          .callsArgWith(1, null, { statusCode: 500 }, '')
-        ctx.DocumentUpdaterManager.getDocument(
-          ctx.project_id,
-          ctx.doc_id,
-          ctx.fromVersion,
-          ctx.callback
+        const error = new ctx.RequestFailedError(
+          'error',
+          'url',
+          {},
+          { status: 500 },
+          null
         )
+        ctx.fetchJson.rejects(error)
       })
 
-      it('should return the callback with an error', function (ctx) {
-        ctx.callback.called.should.equal(true)
-        ctx.callback
-          .calledWith(
-            sinon.match({
-              message: 'doc updater returned a non-success status code',
-              info: {
-                action: 'getDocument',
-                statusCode: 500,
-              },
-            })
+      it('should throw an error', async function (ctx) {
+        const error = await expect(
+          ctx.DocumentUpdaterManager.promises.getDocument(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.fromVersion
           )
-          .should.equal(true)
+        ).to.be.rejected
+        error.message.should.equal(
+          'doc updater returned a non-success status code'
+        )
+        error.info.action.should.equal('getDocument')
+        error.info.statusCode.should.equal(500)
         ctx.logger.error.called.should.equal(false)
       })
     })
   })
 
   describe('flushProjectToMongoAndDelete', function () {
-    beforeEach(function (ctx) {
-      ctx.callback = sinon.stub()
-    })
-
     describe('successfully', function () {
-      beforeEach(function (ctx) {
-        ctx.request.del = sinon
-          .stub()
-          .callsArgWith(1, null, { statusCode: 204 }, '')
-        ctx.DocumentUpdaterManager.flushProjectToMongoAndDelete(
-          ctx.project_id,
-          ctx.callback
+      beforeEach(async function (ctx) {
+        ctx.fetchNothing.resolves()
+        await ctx.DocumentUpdaterManager.promises.flushProjectToMongoAndDelete(
+          ctx.project_id
         )
       })
 
       it('should delete the project from the document updater', function (ctx) {
         const url = `${ctx.settings.apis.documentupdater.url}/project/${ctx.project_id}?background=true`
-        ctx.request.del.calledWith(url).should.equal(true)
-      })
-
-      it('should call the callback with no error', function (ctx) {
-        ctx.callback.calledWith(null).should.equal(true)
+        ctx.fetchNothing
+          .calledWith(url, { method: 'DELETE' })
+          .should.equal(true)
       })
     })
 
     describe('when the document updater API returns an error', function () {
       beforeEach(function (ctx) {
-        ctx.request.del = sinon
-          .stub()
-          .callsArgWith(
-            1,
-            (ctx.error = new Error('something went wrong')),
-            null,
-            null
-          )
-        ctx.DocumentUpdaterManager.flushProjectToMongoAndDelete(
-          ctx.project_id,
-          ctx.callback
-        )
+        ctx.error = new Error('something went wrong')
+        ctx.fetchNothing.rejects(ctx.error)
       })
 
-      it('should return an error to the callback', function (ctx) {
-        ctx.callback.calledWith(ctx.error).should.equal(true)
+      it('should throw an error', async function (ctx) {
+        await expect(
+          ctx.DocumentUpdaterManager.promises.flushProjectToMongoAndDelete(
+            ctx.project_id
+          )
+        ).to.be.rejectedWith(ctx.error)
       })
     })
 
     describe('when the document updater returns a failure error code', function () {
       beforeEach(function (ctx) {
-        ctx.request.del = sinon
-          .stub()
-          .callsArgWith(1, null, { statusCode: 500 }, '')
-        ctx.DocumentUpdaterManager.flushProjectToMongoAndDelete(
-          ctx.project_id,
-          ctx.callback
+        const error = new ctx.RequestFailedError(
+          'error',
+          'url',
+          {},
+          { status: 500 },
+          null
         )
+        ctx.fetchNothing.rejects(error)
       })
 
-      it('should return the callback with an error', function (ctx) {
-        ctx.callback.called.should.equal(true)
-        ctx.callback
-          .calledWith(
-            sinon.match({
-              message: 'doc updater returned a non-success status code',
-              info: {
-                action: 'flushProjectToMongoAndDelete',
-                statusCode: 500,
-              },
-            })
+      it('should throw an error', async function (ctx) {
+        const error = await expect(
+          ctx.DocumentUpdaterManager.promises.flushProjectToMongoAndDelete(
+            ctx.project_id
           )
-          .should.equal(true)
+        ).to.be.rejected
+        error.message.should.equal(
+          'doc updater returned a non-success status code'
+        )
+        error.info.action.should.equal('flushProjectToMongoAndDelete')
+        error.info.statusCode.should.equal(500)
       })
     })
   })
@@ -260,22 +243,15 @@ describe('DocumentUpdaterManager', function () {
         op: [{ d: 'test', p: 345 }],
         v: 789,
       }
-      ctx.rclient.rpush = sinon.stub().yields()
-      ctx.callback = sinon.stub()
+      ctx.rclient.rpush = sinon.stub().resolves()
     })
 
     describe('successfully', function () {
-      beforeEach(function (ctx) {
-        ctx.pendingUpdateListKey = `pending-updates-list-key-${Math.random()}`
-
-        ctx.DocumentUpdaterManager._getPendingUpdateListKey = sinon
-          .stub()
-          .returns(ctx.pendingUpdateListKey)
-        ctx.DocumentUpdaterManager.queueChange(
+      beforeEach(async function (ctx) {
+        await ctx.DocumentUpdaterManager.promises.queueChange(
           ctx.project_id,
           ctx.doc_id,
-          ctx.change,
-          ctx.callback
+          ctx.change
         )
       })
 
@@ -289,12 +265,12 @@ describe('DocumentUpdaterManager', function () {
       })
 
       it('should notify the doc updater of the change via the pending-updates-list queue', function (ctx) {
-        ctx.rclient.rpush
-          .calledWith(
-            ctx.pendingUpdateListKey,
-            `${ctx.project_id}:${ctx.doc_id}`
-          )
-          .should.equal(true)
+        // The second call should be to a pending-updates-list key (either base or sharded)
+        const secondCall = ctx.rclient.rpush.secondCall
+        secondCall.should.exist
+        const queueKey = secondCall.args[0]
+        queueKey.should.match(/^pending-updates-list(-\d+)?$/)
+        secondCall.args[1].should.equal(`${ctx.project_id}:${ctx.doc_id}`)
       })
     })
 
@@ -302,17 +278,17 @@ describe('DocumentUpdaterManager', function () {
       beforeEach(function (ctx) {
         ctx.rclient.rpush = sinon
           .stub()
-          .yields(new Error('something went wrong'))
-        ctx.DocumentUpdaterManager.queueChange(
-          ctx.project_id,
-          ctx.doc_id,
-          ctx.change,
-          ctx.callback
-        )
+          .rejects(new Error('something went wrong'))
       })
 
-      it('should return an error', function (ctx) {
-        ctx.callback.calledWithExactly(sinon.match(Error)).should.equal(true)
+      it('should throw an error', async function (ctx) {
+        await expect(
+          ctx.DocumentUpdaterManager.promises.queueChange(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.change
+          )
+        ).to.be.rejected
       })
     })
 
@@ -321,23 +297,30 @@ describe('DocumentUpdaterManager', function () {
         ctx.stringifyStub = sinon
           .stub(JSON, 'stringify')
           .callsFake(() => '["bad bytes! \u0000 <- here"]')
-        ctx.DocumentUpdaterManager.queueChange(
-          ctx.project_id,
-          ctx.doc_id,
-          ctx.change,
-          ctx.callback
-        )
       })
 
       afterEach(function (ctx) {
         ctx.stringifyStub.restore()
       })
 
-      it('should return an error', function (ctx) {
-        ctx.callback.calledWithExactly(sinon.match(Error)).should.equal(true)
+      it('should throw an error', async function (ctx) {
+        await expect(
+          ctx.DocumentUpdaterManager.promises.queueChange(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.change
+          )
+        ).to.be.rejected
       })
 
-      it('should not push the change onto the pending-updates-list queue', function (ctx) {
+      it('should not push the change onto the pending-updates-list queue', async function (ctx) {
+        await expect(
+          ctx.DocumentUpdaterManager.promises.queueChange(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.change
+          )
+        ).to.be.rejected
         ctx.rclient.rpush.called.should.equal(false)
       })
     })
@@ -347,38 +330,51 @@ describe('DocumentUpdaterManager', function () {
         ctx.change = {
           op: { p: 12, t: 'update is too large'.repeat(1024 * 400) },
         }
-        ctx.DocumentUpdaterManager.queueChange(
-          ctx.project_id,
-          ctx.doc_id,
-          ctx.change,
-          ctx.callback
-        )
       })
 
-      it('should return an error', function (ctx) {
-        ctx.callback.calledWithExactly(sinon.match(Error)).should.equal(true)
+      it('should throw an error', async function (ctx) {
+        await expect(
+          ctx.DocumentUpdaterManager.promises.queueChange(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.change
+          )
+        ).to.be.rejected
       })
 
-      it('should add the size to the error', function (ctx) {
-        ctx.callback.args[0][0].info.updateSize.should.equal(7782422)
+      it('should add the size to the error', async function (ctx) {
+        const error = await expect(
+          ctx.DocumentUpdaterManager.promises.queueChange(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.change
+          )
+        ).to.be.rejected
+        error.info.updateSize.should.equal(7782422)
       })
 
-      it('should not push the change onto the pending-updates-list queue', function (ctx) {
+      it('should not push the change onto the pending-updates-list queue', async function (ctx) {
+        await expect(
+          ctx.DocumentUpdaterManager.promises.queueChange(
+            ctx.project_id,
+            ctx.doc_id,
+            ctx.change
+          )
+        ).to.be.rejected
         ctx.rclient.rpush.called.should.equal(false)
       })
     })
 
     describe('with invalid keys', function () {
-      beforeEach(function (ctx) {
+      beforeEach(async function (ctx) {
         ctx.change = {
           op: [{ d: 'test', p: 345 }],
           version: 789, // not a valid key
         }
-        ctx.DocumentUpdaterManager.queueChange(
+        await ctx.DocumentUpdaterManager.promises.queueChange(
           ctx.project_id,
           ctx.doc_id,
-          ctx.change,
-          ctx.callback
+          ctx.change
         )
       })
 
diff --git a/services/real-time/test/unit/js/WebsocketController.test.js b/services/real-time/test/unit/js/WebsocketController.test.js
index 776b9e79ce..fa57d0fccd 100644
--- a/services/real-time/test/unit/js/WebsocketController.test.js
+++ b/services/real-time/test/unit/js/WebsocketController.test.js
@@ -550,7 +550,12 @@ describe('WebsocketController', function () {
         .callsArgWith(2, null)
       ctx.DocumentUpdaterManager.getDocument = sinon
         .stub()
-        .callsArgWith(3, null, ctx.doc_lines, ctx.version, ctx.ranges, ctx.ops)
+        .callsArgWith(3, null, {
+          lines: ctx.doc_lines,
+          version: ctx.version,
+          ranges: ctx.ranges,
+          ops: ctx.ops,
+        })
       ctx.RoomManager.joinDoc = sinon.stub().callsArg(2)
     })
 
@@ -937,7 +942,12 @@ describe('WebsocketController', function () {
           callback
         ) => {
           ctx.client.disconnected = true
-          callback(null, ctx.doc_lines, ctx.version, ctx.ranges, ctx.ops)
+          return callback(null, {
+            lines: ctx.doc_lines,
+            version: ctx.version,
+            ranges: ctx.ranges,
+            ops: ctx.ops,
+          })
         }
 
         ctx.WebsocketController.joinDoc(