diff --git a/benchmarks/ensureIndex.js b/benchmarks/ensureIndex.js
index 43b06b7..cf33c16 100755
--- a/benchmarks/ensureIndex.js
+++ b/benchmarks/ensureIndex.js
@@ -1,5 +1,5 @@
-const async = require('async')
 const program = require('commander')
+const { apply, waterfall } = require('../test/utils.test.js')
 const Datastore = require('../lib/datastore')
 const commonUtilities = require('./commonUtilities')
 const Profiler = require('./profiler')
@@ -19,8 +19,8 @@ console.log('----------------------------')
 console.log('Test with ' + n + ' documents')
 console.log('----------------------------')
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(function (err) {
       if (err) { return cb(err) }
@@ -28,7 +28,7 @@ async.waterfall([
     })
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.insertDocs, d, n, profiler),
   function (cb) {
     let i
 
@@ -41,6 +41,7 @@ async.waterfall([
 
     console.log('Average time for one ensureIndex: ' + (profiler.elapsedSinceLastStep() / n) + 'ms')
     profiler.step('Finished calling ensureIndex ' + n + ' times')
+    cb()
   }
 ], function (err) {
   profiler.step('Benchmark finished')
diff --git a/benchmarks/find.js b/benchmarks/find.js
index b81b03d..d3c9a83 100755
--- a/benchmarks/find.js
+++ b/benchmarks/find.js
@@ -1,4 +1,4 @@
-const async = require('async')
+const { apply, waterfall } = require('../test/utils.test.js')
 const commonUtilities = require('./commonUtilities')
 const Profiler = require('./profiler')
 
@@ -8,8 +8,8 @@ const config = commonUtilities.getConfiguration(benchDb)
 const d = config.d
 const n = config.n
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(function (err) {
       if (err) { return cb(err) }
@@ -18,8 +18,8 @@ async.waterfall([
     })
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
-  async.apply(commonUtilities.findDocs, d, n, profiler)
+  apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.findDocs, d, n, profiler)
 ], function (err) {
   profiler.step('Benchmark finished')
 
diff --git a/benchmarks/findOne.js b/benchmarks/findOne.js
index 93911bd..b965709 100755
--- a/benchmarks/findOne.js
+++ b/benchmarks/findOne.js
@@ -1,4 +1,4 @@
-const async = require('async')
+const { apply, waterfall } = require('../test/utils.test.js')
 const commonUtilities = require('./commonUtilities')
 const Profiler = require('./profiler')
 
@@ -8,8 +8,8 @@ const config = commonUtilities.getConfiguration(benchDb)
 const d = config.d
 const n = config.n
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(function (err) {
       if (err) { return cb(err) }
@@ -18,9 +18,9 @@ async.waterfall([
     })
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.insertDocs, d, n, profiler),
   function (cb) { setTimeout(function () { cb() }, 500) },
-  async.apply(commonUtilities.findOneDocs, d, n, profiler)
+  apply(commonUtilities.findOneDocs, d, n, profiler)
 ], function (err) {
   profiler.step('Benchmark finished')
 
diff --git a/benchmarks/findWithIn.js b/benchmarks/findWithIn.js
index e167a6f..8df0c41 100755
--- a/benchmarks/findWithIn.js
+++ b/benchmarks/findWithIn.js
@@ -1,4 +1,4 @@
-const async = require('async')
+const { apply, waterfall } = require('../test/utils.test.js')
 const commonUtilities = require('./commonUtilities')
 const Profiler = require('./profiler')
 
@@ -8,8 +8,8 @@ const config = commonUtilities.getConfiguration(benchDb)
 const d = config.d
 const n = config.n
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(function (err) {
       if (err) { return cb(err) }
@@ -18,8 +18,8 @@ async.waterfall([
     })
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
-  async.apply(commonUtilities.findDocsWithIn, d, n, profiler)
+  apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.findDocsWithIn, d, n, profiler)
 ], function (err) {
   profiler.step('Benchmark finished')
 
diff --git a/benchmarks/insert.js b/benchmarks/insert.js
index f78d8b5..4938212 100755
--- a/benchmarks/insert.js
+++ b/benchmarks/insert.js
@@ -1,4 +1,4 @@
-const async = require('async')
+const { apply, waterfall } = require('../test/utils.test.js')
 const commonUtilities = require('./commonUtilities')
 const Profiler = require('./profiler')
 
@@ -8,8 +8,8 @@ const config = commonUtilities.getConfiguration(benchDb)
 const d = config.d
 let n = config.n
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(function (err) {
       if (err) { return cb(err) }
@@ -24,7 +24,7 @@ async.waterfall([
     })
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler)
+  apply(commonUtilities.insertDocs, d, n, profiler)
 ], function (err) {
   profiler.step('Benchmark finished')
 
diff --git a/benchmarks/loadDatabase.js b/benchmarks/loadDatabase.js
index a9910d3..b007dfb 100755
--- a/benchmarks/loadDatabase.js
+++ b/benchmarks/loadDatabase.js
@@ -1,4 +1,4 @@
-const async = require('async')
+const { apply, waterfall } = require('../test/utils.test.js')
 const program = require('commander')
 const Datastore = require('../lib/datastore')
 const commonUtilities = require('./commonUtilities')
@@ -20,14 +20,14 @@ console.log('Test with ' + n + ' documents')
 console.log(program.withIndex ? 'Use an index' : "Don't use an index")
 console.log('----------------------------')
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(cb)
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
-  async.apply(commonUtilities.loadDatabase, d, n, profiler)
+  apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.loadDatabase, d, n, profiler)
 ], function (err) {
   profiler.step('Benchmark finished')
 
diff --git a/benchmarks/profiler.js b/benchmarks/profiler.js
index a5d73af..184aed2 100644
--- a/benchmarks/profiler.js
+++ b/benchmarks/profiler.js
@@ -1,3 +1,4 @@
+const { apply, waterfall } = require('../test/utils.test.js')
 const util = require('util')
 
 function formatTime (time, precision) {
diff --git a/benchmarks/remove.js b/benchmarks/remove.js
index a262d52..e3607f2 100755
--- a/benchmarks/remove.js
+++ b/benchmarks/remove.js
@@ -1,4 +1,4 @@
-const async = require('async')
+const { apply, waterfall } = require('../test/utils.test.js')
 const commonUtilities = require('./commonUtilities')
 const Profiler = require('./profiler')
 
@@ -8,8 +8,8 @@ const config = commonUtilities.getConfiguration(benchDb)
 const d = config.d
 const n = config.n
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(function (err) {
       if (err) { return cb(err) }
@@ -18,16 +18,16 @@ async.waterfall([
     })
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.insertDocs, d, n, profiler),
 
   // Test with remove only one document
   function (cb) { profiler.step('MULTI: FALSE'); return cb() },
-  async.apply(commonUtilities.removeDocs, { multi: false }, d, n, profiler),
+  apply(commonUtilities.removeDocs, { multi: false }, d, n, profiler),
   // Test with multiple documents
   function (cb) { d.remove({}, { multi: true }, function () { return cb() }) },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.insertDocs, d, n, profiler),
   function (cb) { profiler.step('MULTI: TRUE'); return cb() },
-  async.apply(commonUtilities.removeDocs, { multi: true }, d, n, profiler)
+  apply(commonUtilities.removeDocs, { multi: true }, d, n, profiler)
 ], function (err) {
   profiler.step('Benchmark finished')
 
diff --git a/benchmarks/update.js b/benchmarks/update.js
index 1304f2f..f36dfd8 100755
--- a/benchmarks/update.js
+++ b/benchmarks/update.js
@@ -1,4 +1,4 @@
-const async = require('async')
+const { apply, waterfall } = require('../test/utils.test.js')
 const commonUtilities = require('./commonUtilities')
 const Profiler = require('./profiler')
 
@@ -8,8 +8,8 @@ const config = commonUtilities.getConfiguration(benchDb)
 const d = config.d
 const n = config.n
 
-async.waterfall([
-  async.apply(commonUtilities.prepareDb, benchDb),
+waterfall([
+  apply(commonUtilities.prepareDb, benchDb),
   function (cb) {
     d.loadDatabase(function (err) {
       if (err) { return cb(err) }
@@ -18,18 +18,18 @@ async.waterfall([
     })
   },
   function (cb) { profiler.beginProfiling(); return cb() },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.insertDocs, d, n, profiler),
 
   // Test with update only one document
   function (cb) { profiler.step('MULTI: FALSE'); return cb() },
-  async.apply(commonUtilities.updateDocs, { multi: false }, d, n, profiler),
+  apply(commonUtilities.updateDocs, { multi: false }, d, n, profiler),
 
   // Test with multiple documents
   // eslint-disable-next-line node/handle-callback-err
   function (cb) { d.remove({}, { multi: true }, function (err) { return cb() }) },
-  async.apply(commonUtilities.insertDocs, d, n, profiler),
+  apply(commonUtilities.insertDocs, d, n, profiler),
   function (cb) { profiler.step('MULTI: TRUE'); return cb() },
-  async.apply(commonUtilities.updateDocs, { multi: true }, d, n, profiler)
+  apply(commonUtilities.updateDocs, { multi: true }, d, n, profiler)
 ], function (err) {
   profiler.step('Benchmark finished')
 
diff --git a/karma.conf.template.js b/karma.conf.template.js
index ce493df..0eab6eb 100644
--- a/karma.conf.template.js
+++ b/karma.conf.template.js
@@ -14,7 +14,7 @@ module.exports = (config) => ({
   // list of files / patterns to load in the browser
   files: [
     'node_modules/localforage/dist/localforage.min.js',
-    'node_modules/async/lib/async.js',
+    'browser-version/out/testUtils.min.js',
     'browser-version/out/nedb.min.js',
     'test/browser/nedb-browser.spec.js',
     'test/browser/load.spec.js'
diff --git a/package-lock.json b/package-lock.json
index 7e078d1..ece5684 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -15,7 +15,6 @@
       "devDependencies": {
         "@react-native-async-storage/async-storage": "^1.15.9",
         "@types/jest": "^27.0.2",
-        "async": "0.2.10",
         "browser-resolve": "^2.0.0",
         "chai": "^4.3.4",
         "commander": "^7.2.0",
@@ -20073,8 +20072,7 @@
       "dev": true
     },
     "async": {
-      "version": "0.2.10",
-      "resolved": "https://registry.npmjs.org/async/-/async-0.2.10.tgz",
+      "version": "https://registry.npmjs.org/async/-/async-0.2.10.tgz",
       "integrity": "sha1-trvgsGdLnXGXCMo43owjfLUmw9E=",
       "dev": true
     },
diff --git a/package.json b/package.json
index 149d4d8..159f881 100755
--- a/package.json
+++ b/package.json
@@ -48,7 +48,6 @@
     "@react-native-async-storage/async-storage": "^1.15.9",
     "@types/jest": "^27.0.2",
     "browser-resolve": "^2.0.0",
-    "async": "0.2.10",
     "chai": "^4.3.4",
     "commander": "^7.2.0",
     "events": "^3.3.0",
diff --git a/test/browser/load.spec.js b/test/browser/load.spec.js
index 4390a19..b2a6b39 100755
--- a/test/browser/load.spec.js
+++ b/test/browser/load.spec.js
@@ -1,5 +1,5 @@
 /* eslint-env mocha, browser */
-/* global async, Nedb, localforage */
+/* global Nedb, localforage, testUtils */
 
 const N = 5000
 const db = new Nedb({ filename: 'loadTest', autoload: true })
@@ -9,7 +9,7 @@ const sample = JSON.stringify({ data: Math.random(), _id: Math.random() })
 const someInserts = (sn, N, callback) => {
   const beg = Date.now()
   let i = 0
-  async.whilst(() => i < N, _cb => {
+  testUtils.whilst(() => i < N, _cb => {
     db.insert({ data: Math.random() }, err => { i += 1; return _cb(err) })
   }, err => {
     console.log('Inserts, series ' + sn + ' ' + (Date.now() - beg))
@@ -41,7 +41,7 @@ const someLSDiff = (sn, N, callback) => {
 function someLF (sn, N, callback) {
   const beg = Date.now()
   let i = 0
-  async.whilst(() => i < N, _cb => {
+  testUtils.whilst(() => i < N, _cb => {
     localforage.getItem('loadTestLF', (err, value) => {
       if (err) return _cb(err)
       localforage.setItem('loadTestLF', value + sample, err => { i += 1; return _cb(err) })
@@ -56,7 +56,7 @@ function someLF (sn, N, callback) {
 const someLFDiff = (sn, N, callback) => {
   const beg = Date.now()
   let i = 0
-  async.whilst(() => i < N, _cb => {
+  testUtils.whilst(() => i < N, _cb => {
     localforage.setItem('loadTestLF-' + i, sample, err => { i += 1; return _cb(err) })
   }, err => {
     console.log('localForage/IDB, series ' + sn + ' ' + (Date.now() - beg))
@@ -72,54 +72,54 @@ describe.skip('Load tests', function () {
     db.remove({}, { multi: true }, err => done(err))
   })
 
-  it.skip('Inserts', function (done) {
-    async.waterfall([
+  it('Inserts', function (done) {
+    testUtils.waterfall([
       // Slow and gets slower with database size
-      async.apply(someInserts, '#1', N), // N=5000, 141s
-      async.apply(someInserts, '#2', N), // N=5000, 208s
-      async.apply(someInserts, '#3', N), // N=5000, 281s
-      async.apply(someInserts, '#4', N) // N=5000, 350s
+      testUtils.apply(someInserts, '#1', N), // N=5000, 141s
+      testUtils.apply(someInserts, '#2', N), // N=5000, 208s
+      testUtils.apply(someInserts, '#3', N), // N=5000, 281s
+      testUtils.apply(someInserts, '#4', N) // N=5000, 350s
     ], done)
   })
 
-  it.skip('Localstorage', function (done) {
-    async.waterfall([
+  it('Localstorage', function (done) {
+    testUtils.waterfall([
       // Slow and gets slower really fast with database size, then outright crashes
-      async.apply(someLS, '#1', N), // N=4000, 2.5s
-      async.apply(someLS, '#2', N), // N=4000, 8.0s
-      async.apply(someLS, '#3', N), // N=4000, 26.5s
-      async.apply(someLS, '#4', N) // N=4000, 47.8s then crash, can't get string (with N=5000 crash happens on second pass)
+      testUtils.apply(someLS, '#1', N), // N=4000, 2.5s
+      testUtils.apply(someLS, '#2', N), // N=4000, 8.0s
+      testUtils.apply(someLS, '#3', N), // N=4000, 26.5s
+      testUtils.apply(someLS, '#4', N) // N=4000, 47.8s then crash, can't get string (with N=5000 crash happens on second pass)
     ], done)
   })
 
-  it.skip('Localstorage Diff', function (done) {
-    async.waterfall([
+  it('Localstorage Diff', function (done) {
+    testUtils.waterfall([
       // Much faster and more consistent
-      async.apply(someLSDiff, '#1', N), // N=50000, 0.7s
-      async.apply(someLSDiff, '#2', N), // N=50000, 0.5s
-      async.apply(someLSDiff, '#3', N), // N=50000, 0.5s
-      async.apply(someLSDiff, '#4', N) // N=50000, 0.5s
+      testUtils.apply(someLSDiff, '#1', N), // N=50000, 0.7s
+      testUtils.apply(someLSDiff, '#2', N), // N=50000, 0.5s
+      testUtils.apply(someLSDiff, '#3', N), // N=50000, 0.5s
+      testUtils.apply(someLSDiff, '#4', N) // N=50000, 0.5s
     ], done)
   })
 
-  it.skip('LocalForage', function (done) {
-    async.waterfall([
+  it('LocalForage', function (done) {
+    testUtils.waterfall([
       // Slow and gets slower with database size
       cb => { localforage.setItem('loadTestLF', '', err => cb(err)) },
-      async.apply(someLF, '#1', N), // N=5000, 69s
-      async.apply(someLF, '#2', N), // N=5000, 108s
-      async.apply(someLF, '#3', N), // N=5000, 137s
-      async.apply(someLF, '#4', N) // N=5000, 169s
+      testUtils.apply(someLF, '#1', N), // N=5000, 69s
+      testUtils.apply(someLF, '#2', N), // N=5000, 108s
+      testUtils.apply(someLF, '#3', N), // N=5000, 137s
+      testUtils.apply(someLF, '#4', N) // N=5000, 169s
     ], done)
   })
 
-  it.skip('LocalForage diff', function (done) {
-    async.waterfall([
+  it('LocalForage diff', function (done) {
+    testUtils.waterfall([
       // Quite fast and speed doesn't change with database size (tested with N=10000 and N=50000, still no slow-down)
-      async.apply(someLFDiff, '#1', N), // N=5000, 18s
-      async.apply(someLFDiff, '#2', N), // N=5000, 18s
-      async.apply(someLFDiff, '#3', N), // N=5000, 18s
-      async.apply(someLFDiff, '#4', N) // N=5000, 18s
+      testUtils.apply(someLFDiff, '#1', N), // N=5000, 18s
+      testUtils.apply(someLFDiff, '#2', N), // N=5000, 18s
+      testUtils.apply(someLFDiff, '#3', N), // N=5000, 18s
+      testUtils.apply(someLFDiff, '#4', N) // N=5000, 18s
     ], done)
   })
 })
diff --git a/test/cursor.test.js b/test/cursor.test.js
index 42d8566..fbce0c4 100755
--- a/test/cursor.test.js
+++ b/test/cursor.test.js
@@ -3,7 +3,7 @@ const chai = require('chai')
 const testDb = 'workspace/test.db'
 const fs = require('fs')
 const path = require('path')
-const async = require('async')
+const { each, waterfall } = require('./utils.test.js')
 const Datastore = require('../lib/datastore')
 const Persistence = require('../lib/persistence')
 const Cursor = require('../lib/cursor')
@@ -19,7 +19,7 @@ describe('Cursor', function () {
     d.filename.should.equal(testDb)
     d.inMemoryOnly.should.equal(false)
 
-    async.waterfall([
+    waterfall([
       function (cb) {
         Persistence.ensureDirectoryExists(path.dirname(testDb), function () {
           fs.access(testDb, fs.constants.F_OK, function (err) {
@@ -58,7 +58,7 @@ describe('Cursor', function () {
     })
 
     it('Without query, an empty query or a simple query and no skip or limit', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           const cursor = new Cursor(d)
           cursor.exec(function (err, docs) {
@@ -100,7 +100,7 @@ describe('Cursor', function () {
     })
 
     it('With an empty collection', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) { return cb(err) })
         },
@@ -222,7 +222,7 @@ describe('Cursor', function () {
     })
 
     it('With an empty collection', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) { return cb(err) })
         },
@@ -240,7 +240,7 @@ describe('Cursor', function () {
 
     it('Ability to chain sorting and exec', function (done) {
       let i
-      async.waterfall([
+      waterfall([
         function (cb) {
           const cursor = new Cursor(d)
           cursor.sort({ age: 1 }).exec(function (err, docs) {
@@ -267,7 +267,7 @@ describe('Cursor', function () {
     })
 
     it('Using limit and sort', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           const cursor = new Cursor(d)
           cursor.sort({ age: 1 }).limit(3).exec(function (err, docs) {
@@ -293,7 +293,7 @@ describe('Cursor', function () {
     })
 
     it('Using a limit higher than total number of docs shouldnt cause an error', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           const cursor = new Cursor(d)
           cursor.sort({ age: 1 }).limit(7).exec(function (err, docs) {
@@ -311,7 +311,7 @@ describe('Cursor', function () {
     })
 
     it('Using limit and skip with sort', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           const cursor = new Cursor(d)
           cursor.sort({ age: 1 }).limit(1).skip(2).exec(function (err, docs) {
@@ -346,7 +346,7 @@ describe('Cursor', function () {
     })
 
     it('Using too big a limit and a skip with sort', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           const cursor = new Cursor(d)
           cursor.sort({ age: 1 }).limit(8).skip(2).exec(function (err, docs) {
@@ -362,7 +362,7 @@ describe('Cursor', function () {
     })
 
     it('Using too big a skip with sort should return no result', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           const cursor = new Cursor(d)
           cursor.sort({ age: 1 }).skip(5).exec(function (err, docs) {
@@ -399,7 +399,7 @@ describe('Cursor', function () {
     })
 
     it('Sorting strings', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) {
             if (err) { return cb(err) }
@@ -443,7 +443,7 @@ describe('Cursor', function () {
       let doc2
       let doc3
 
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) {
             if (err) { return cb(err) }
@@ -489,7 +489,7 @@ describe('Cursor', function () {
     })
 
     it('Sorting when some fields are undefined', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) {
             if (err) { return cb(err) }
@@ -537,7 +537,7 @@ describe('Cursor', function () {
     })
 
     it('Sorting when all fields are undefined', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) {
             if (err) { return cb(err) }
@@ -571,7 +571,7 @@ describe('Cursor', function () {
     })
 
     it('Multiple consecutive sorts', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) {
             if (err) { return cb(err) }
@@ -655,7 +655,7 @@ describe('Cursor', function () {
       const companies = ['acme', 'milkman', 'zoinks']
       const entities = []
 
-      async.waterfall([
+      waterfall([
         function (cb) {
           d.remove({}, { multi: true }, function (err) {
             if (err) { return cb(err) }
@@ -672,7 +672,7 @@ describe('Cursor', function () {
               }
             }
 
-            async.each(entities, function (entity, callback) {
+            each(entities, function (entity, callback) {
               d.insert(entity, function () {
                 callback()
               })
diff --git a/test/db.test.js b/test/db.test.js
index aff8e50..a11fef2 100755
--- a/test/db.test.js
+++ b/test/db.test.js
@@ -3,7 +3,7 @@ const chai = require('chai')
 const testDb = 'workspace/test.db'
 const fs = require('fs')
 const path = require('path')
-const async = require('async')
+const { apply, each, waterfall } = require('./utils.test.js')
 const model = require('../lib/model')
 const Datastore = require('../lib/datastore')
 const Persistence = require('../lib/persistence')
@@ -20,7 +20,7 @@ describe('Database', function () {
     d.filename.should.equal(testDb)
     d.inMemoryOnly.should.equal(false)
 
-    async.waterfall([
+    waterfall([
       function (cb) {
         Persistence.ensureDirectoryExists(path.dirname(testDb), function () {
           fs.access(testDb, fs.constants.FS_OK, function (err) {
@@ -697,7 +697,7 @@ describe('Database', function () {
 
   describe('Find', function () {
     it('Can find all documents if an empty query is used', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err) {
@@ -722,7 +722,7 @@ describe('Database', function () {
     })
 
     it('Can find all documents matching a basic query', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err) {
@@ -751,7 +751,7 @@ describe('Database', function () {
     })
 
     it('Can find one document matching a basic query and return null if none is found', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err) {
@@ -1025,7 +1025,7 @@ describe('Database', function () {
 
   describe('Count', function () {
     it('Count all documents if an empty query is used', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err) {
@@ -1046,7 +1046,7 @@ describe('Database', function () {
     })
 
     it('Count all documents matching a basic query', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err) {
@@ -1115,7 +1115,7 @@ describe('Database', function () {
 
   describe('Update', function () {
     it('If the query doesn\'t match anything, database is not modified', function (done) {
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err) {
@@ -1212,7 +1212,7 @@ describe('Database', function () {
       }
 
       // Actually launch the tests
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err, doc1) {
@@ -1234,11 +1234,11 @@ describe('Database', function () {
             return cb()
           })
         },
-        async.apply(testPostUpdateState),
+        apply(testPostUpdateState),
         function (cb) {
           d.loadDatabase(function (err) { cb(err) })
         },
-        async.apply(testPostUpdateState)
+        apply(testPostUpdateState)
       ], done)
     })
 
@@ -1274,7 +1274,7 @@ describe('Database', function () {
       }
 
       // Actually launch the test
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err, doc1) {
@@ -1296,11 +1296,11 @@ describe('Database', function () {
             return cb()
           })
         },
-        async.apply(testPostUpdateState),
+        apply(testPostUpdateState),
         function (cb) {
           d.loadDatabase(function (err) { return cb(err) })
         },
-        async.apply(testPostUpdateState) // The persisted state has been updated
+        apply(testPostUpdateState) // The persisted state has been updated
       ], done)
     })
 
@@ -1895,7 +1895,7 @@ describe('Database', function () {
       }
 
       // Actually launch the test
-      async.waterfall([
+      waterfall([
         function (cb) {
           // eslint-disable-next-line node/handle-callback-err
           d.insert({ somedata: 'ok' }, function (err, doc1) {
@@ -1915,11 +1915,11 @@ describe('Database', function () {
             return cb()
           })
         },
-        async.apply(testPostUpdateState),
+        apply(testPostUpdateState),
         function (cb) {
           d.loadDatabase(function (err) { return cb(err) })
         },
-        async.apply(testPostUpdateState)
+        apply(testPostUpdateState)
       ], done)
     })
 
@@ -1934,7 +1934,7 @@ describe('Database', function () {
 
               // Remove two docs simultaneously
               const toRemove = ['Mars', 'Saturn']
-              async.each(toRemove, function (planet, cb) {
+              each(toRemove, function (planet, cb) {
                 d.remove({ planet: planet }, function (err) { return cb(err) })
                 // eslint-disable-next-line node/handle-callback-err
               }, function (err) {
diff --git a/test/executor.test.js b/test/executor.test.js
index fda65ff..a9d2de9 100755
--- a/test/executor.test.js
+++ b/test/executor.test.js
@@ -3,7 +3,7 @@ const chai = require('chai')
 const testDb = 'workspace/test.db'
 const fs = require('fs')
 const path = require('path')
-const async = require('async')
+const { waterfall } = require('./utils.test.js')
 const Datastore = require('../lib/datastore')
 const Persistence = require('../lib/persistence')
 
@@ -151,7 +151,7 @@ describe('Executor', function () {
       d.filename.should.equal(testDb)
       d.inMemoryOnly.should.equal(false)
 
-      async.waterfall([
+      waterfall([
         function (cb) {
           Persistence.ensureDirectoryExists(path.dirname(testDb), function () {
             fs.access(testDb, fs.constants.F_OK, function (err) {
diff --git a/test/persistence.test.js b/test/persistence.test.js
index 578707b..a19ae04 100755
--- a/test/persistence.test.js
+++ b/test/persistence.test.js
@@ -3,7 +3,7 @@ const chai = require('chai')
 const testDb = 'workspace/test.db'
 const fs = require('fs')
 const path = require('path')
-const async = require('async')
+const { apply, waterfall } = require('./utils.test.js')
 const model = require('../lib/model')
 const Datastore = require('../lib/datastore')
 const Persistence = require('../lib/persistence')
@@ -22,7 +22,7 @@ describe('Persistence', function () {
     d.filename.should.equal(testDb)
     d.inMemoryOnly.should.equal(false)
 
-    async.waterfall([
+    waterfall([
       function (cb) {
         Persistence.ensureDirectoryExists(path.dirname(testDb), function () {
           fs.access(testDb, fs.constants.FS_OK, function (err) {
@@ -911,9 +911,9 @@ describe('Persistence', function () {
       const dbFile = 'workspace/test2.db'
       let theDb, theDb2, doc1, doc2
 
-      async.waterfall([
-        async.apply(storage.ensureFileDoesntExist, dbFile),
-        async.apply(storage.ensureFileDoesntExist, dbFile + '~'),
+      waterfall([
+        apply(storage.ensureFileDoesntExist, dbFile),
+        apply(storage.ensureFileDoesntExist, dbFile + '~'),
         function (cb) {
           theDb = new Datastore({ filename: dbFile })
           theDb.loadDatabase(cb)
diff --git a/test/utils.test.js b/test/utils.test.js
new file mode 100644
index 0000000..2aa5f62
--- /dev/null
+++ b/test/utils.test.js
@@ -0,0 +1,33 @@
+const { callbackify, promisify } = require('util')
+
+const waterfallAsync = async tasks => {
+  for (const task of tasks) {
+    await promisify(task)()
+  }
+}
+
+const waterfall = callbackify(waterfallAsync)
+
+const eachAsync = async (arr, iterator) => Promise.all(arr.map(el => promisify(iterator)(el)))
+
+const each = callbackify(eachAsync)
+
+const apply = function (fn) {
+  const args = Array.prototype.slice.call(arguments, 1)
+  return function () {
+    return fn.apply(
+      null, args.concat(Array.prototype.slice.call(arguments))
+    )
+  }
+}
+
+const whilstAsync = async (test, fn) => {
+  while (test()) await promisify(fn)()
+}
+
+const whilst = callbackify(whilstAsync)
+
+module.exports.whilst = whilst
+module.exports.apply = apply
+module.exports.waterfall = waterfall
+module.exports.each = each
diff --git a/test_lac/openFds.test.js b/test_lac/openFds.test.js
index b93c06d..4512087 100644
--- a/test_lac/openFds.test.js
+++ b/test_lac/openFds.test.js
@@ -1,5 +1,5 @@
 const fs = require('fs')
-const async = require('async')
+const { waterfall, whilst } = require('../test/utils.test.js')
 const Nedb = require('../lib/datastore')
 const db = new Nedb({ filename: './workspace/openfds.db', autoload: true })
 const N = 64
@@ -7,7 +7,7 @@ let i
 let fds
 
 function multipleOpen (filename, N, callback) {
-  async.whilst(function () { return i < N }
+  whilst(function () { return i < N }
     , function (cb) {
       fs.open(filename, 'r', function (err, fd) {
         i += 1
@@ -18,7 +18,7 @@ function multipleOpen (filename, N, callback) {
     , callback)
 }
 
-async.waterfall([
+waterfall([
   // Check that ulimit has been set to the correct value
   function (cb) {
     i = 0
@@ -46,7 +46,7 @@ async.waterfall([
         if (err) { console.log(err) }
 
         i = 0
-        async.whilst(function () { return i < 2 * N + 1 }
+        whilst(function () { return i < 2 * N + 1 }
           , function (cb) {
             db.persistence.persistCachedDatabase(function (err) {
               if (err) { return cb(err) }
@@ -61,4 +61,4 @@ async.waterfall([
       })
     })
   }
-])
+], () => {})
diff --git a/webpack.config.js b/webpack.config.js
index 37a2cb1..6ba8737 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -37,11 +37,12 @@ module.exports = (env, argv) => {
       })
     ],
     entry: {
-      Nedb: path.join(__dirname, 'lib', 'datastore.js')
+      Nedb: path.join(__dirname, 'lib', 'datastore.js'),
+      testUtils: path.join(__dirname, 'test', 'utils.test.js')
     },
     output: {
       path: path.join(__dirname, 'browser-version/out'),
-      filename: minimize ? 'nedb.min.js' : 'nedb.js',
+      filename: `[name]${minimize ? '.min' : ''}.js`,
       libraryTarget: 'window',
       library: '[name]'
     }