diff --git a/services/web/app/src/Features/Referal/ReferalAllocator.js b/services/web/app/src/Features/Referal/ReferalAllocator.js
index 2346839b07..bf42fb840f 100644
--- a/services/web/app/src/Features/Referal/ReferalAllocator.js
+++ b/services/web/app/src/Features/Referal/ReferalAllocator.js
@@ -1,33 +1,22 @@
 const OError = require('@overleaf/o-error')
 const { User } = require('../../models/User')
 const FeaturesUpdater = require('../Subscription/FeaturesUpdater')
-const { promisify } = require('@overleaf/promise-utils')
+const { callbackify } = require('@overleaf/promise-utils')
 
-function allocate(
-  referalId,
-  newUserId,
-  referalSource,
-  referalMedium,
-  callback
-) {
-  if (callback == null) {
-    callback = function () {}
-  }
+async function allocate(referalId, newUserId, referalSource, referalMedium) {
   if (referalId == null) {
-    return callback(null)
+    return null
   }
 
   const query = { referal_id: referalId }
-  User.findOne(query, { _id: 1 }, function (error, user) {
-    if (error != null) {
-      return callback(error)
-    }
-    if (user == null || user._id == null) {
-      return callback(null)
-    }
+  const user = await User.findOne(query, { _id: 1 }).exec()
+  if (user == null || user._id == null) {
+    return null
+  }
 
-    if (referalSource === 'bonus') {
-      User.updateOne(
+  if (referalSource === 'bonus') {
+    try {
+      await User.updateOne(
         query,
         {
           $push: {
@@ -37,27 +26,23 @@ function allocate(
             refered_user_count: 1,
           },
         },
-        {},
-        function (err) {
-          if (err != null) {
-            OError.tag(err, 'something went wrong allocating referal', {
-              referalId,
-              newUserId,
-            })
-            return callback(err)
-          }
-          FeaturesUpdater.refreshFeatures(user._id, 'referral', callback)
-        }
-      )
-    } else {
-      callback()
+        {}
+      ).exec()
+    } catch (err) {
+      OError.tag(err, 'something went wrong allocating referal', {
+        referalId,
+        newUserId,
+      })
+      throw err
     }
-  })
+
+    return await FeaturesUpdater.promises.refreshFeatures(user._id, 'referral')
+  }
 }
 
 module.exports = {
-  allocate,
+  allocate: callbackify(allocate),
   promises: {
-    allocate: promisify(allocate),
+    allocate,
   },
 }
diff --git a/services/web/test/unit/src/Referal/ReferalAllocatorTests.js b/services/web/test/unit/src/Referal/ReferalAllocatorTests.js
index 9adeb74466..ecc0c6ea89 100644
--- a/services/web/test/unit/src/Referal/ReferalAllocatorTests.js
+++ b/services/web/test/unit/src/Referal/ReferalAllocatorTests.js
@@ -16,28 +16,30 @@ describe('ReferalAllocator', function () {
         '@overleaf/settings': (this.Settings = {}),
       },
     })
-    this.callback = sinon.stub()
     this.referal_id = 'referal-id-123'
     this.referal_medium = 'twitter'
     this.user_id = 'user-id-123'
     this.new_user_id = 'new-user-id-123'
-    this.FeaturesUpdater.refreshFeatures = sinon.stub().yields()
-    this.User.updateOne = sinon.stub().callsArgWith(3, null)
-    this.User.findOne = sinon
-      .stub()
-      .callsArgWith(2, null, { _id: this.user_id })
+    this.FeaturesUpdater.promises = {
+      refreshFeatures: sinon.stub().resolves(),
+    }
+    this.User.updateOne = sinon.stub().returns({
+      exec: sinon.stub().resolves(),
+    })
+    this.User.findOne = sinon.stub().returns({
+      exec: sinon.stub().resolves({ _id: this.user_id }),
+    })
   })
 
   describe('allocate', function () {
     describe('when the referal was a bonus referal', function () {
-      beforeEach(function () {
+      beforeEach(async function () {
         this.referal_source = 'bonus'
-        this.ReferalAllocator.allocate(
+        await this.ReferalAllocator.promises.allocate(
           this.referal_id,
           this.new_user_id,
           this.referal_source,
-          this.referal_medium,
-          this.callback
+          this.referal_medium
         )
       })
 
@@ -66,27 +68,24 @@ describe('ReferalAllocator', function () {
       })
 
       it("should refresh the user's subscription", function () {
-        this.FeaturesUpdater.refreshFeatures
+        this.FeaturesUpdater.promises.refreshFeatures
           .calledWith(this.user_id)
           .should.equal(true)
       })
-
-      it('should call the callback', function () {
-        this.callback.called.should.equal(true)
-      })
     })
 
     describe('when there is no user for the referal id', function () {
-      beforeEach(function () {
+      beforeEach(async function () {
         this.referal_source = 'bonus'
         this.referal_id = 'wombat'
-        this.User.findOne = sinon.stub().callsArgWith(2, null, null)
-        this.ReferalAllocator.allocate(
+        this.User.findOne = sinon.stub().returns({
+          exec: sinon.stub().resolves(null),
+        })
+        await this.ReferalAllocator.promises.allocate(
           this.referal_id,
           this.new_user_id,
           this.referal_source,
-          this.referal_medium,
-          this.callback
+          this.referal_medium
         )
       })
 
@@ -101,23 +100,18 @@ describe('ReferalAllocator', function () {
       })
 
       it('should not assign the user a bonus', function () {
-        this.FeaturesUpdater.refreshFeatures.called.should.equal(false)
-      })
-
-      it('should call the callback', function () {
-        this.callback.called.should.equal(true)
+        this.FeaturesUpdater.promises.refreshFeatures.called.should.equal(false)
       })
     })
 
     describe('when the referal is not a bonus referal', function () {
-      beforeEach(function () {
+      beforeEach(async function () {
         this.referal_source = 'public_share'
-        this.ReferalAllocator.allocate(
+        await this.ReferalAllocator.promises.allocate(
           this.referal_id,
           this.new_user_id,
           this.referal_source,
-          this.referal_medium,
-          this.callback
+          this.referal_medium
         )
       })
 
@@ -132,11 +126,7 @@ describe('ReferalAllocator', function () {
       })
 
       it('should not assign the user a bonus', function () {
-        this.FeaturesUpdater.refreshFeatures.called.should.equal(false)
-      })
-
-      it('should call the callback', function () {
-        this.callback.called.should.equal(true)
+        this.FeaturesUpdater.promises.refreshFeatures.called.should.equal(false)
       })
     })
   })