diff --git a/lib/main.js b/lib/main.js
index 18b41a04..4d7b6014 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -616,7 +616,7 @@ Lambda.prototype._listEventSourceMappings = function (lambda, params, cb) {
 
 Lambda.prototype._updateEventSources = (lambda, functionName, existingEventSourceList, eventSourceList, cb) => {
   if (eventSourceList == null) {
-    return cb(null, [])
+    return new Promise(resolve => cb(null, []))
   }
   const updateEventSourceList = []
   // Checking new and update event sources
@@ -705,14 +705,14 @@ Lambda.prototype._updateEventSources = (lambda, functionName, existingEventSourc
 
 Lambda.prototype._updateScheduleEvents = (scheduleEvents, functionArn, scheduleList, cb) => {
   if (scheduleList == null) {
-    return cb(null, [])
+    return new Promise(resolve => cb(null, []))
   }
 
   const paramsList = scheduleList.map((schedule) =>
     Object.assign(schedule, { FunctionArn: functionArn }))
 
   // series
-  paramsList.map((params) => {
+  return paramsList.map((params) => {
     return scheduleEvents.add(params)
   }).reduce((a, b) => {
     return a.then(b)
@@ -812,7 +812,7 @@ Lambda.prototype.deploy = function (program) {
       // Checking function
       return lambda.getFunction({
         'FunctionName': params.FunctionName
-      }, function (err) {
+      }, (err) => {
         if (err) {
           // Function does not exist
           return _this._uploadNew(lambda, params, function (err, results) {
@@ -822,20 +822,36 @@ Lambda.prototype.deploy = function (program) {
             console.log('=> Zip file(s) done uploading. Results follow: ')
             console.log(results)
 
-            async.parallel([
-              function (_callback) {
-                // Updating event source(s)
-                _this._updateEventSources(lambda, params.FunctionName, [], eventSourceList.EventSourceMappings, function (err, results) {
-                  _callback(err, results)
-                })
-              },
-              function (_callback) {
-                _this._updateScheduleEvents(scheduleEvents, results.FunctionArn, eventSourceList.ScheduleEvents, function (err, results) {
-                  _callback(err, results)
-                })
-              }
-            ], function (err, results) {
-              cb(err, results)
+            // This code is on its way to Promise.
+            // From now on, callback will not be used.
+            return Promise.all([
+              new Promise((resolve, reject) => {
+                _this._updateEventSources(
+                  lambda,
+                  params.FunctionName,
+                  [],
+                  eventSourceList.EventSourceMappings,
+                  (err, results) => {
+                    if (err) return reject(err)
+                    resolve(results)
+                  }
+                )
+              }),
+              new Promise((resolve, reject) => {
+                _this._updateScheduleEvents(
+                  scheduleEvents,
+                  results.FunctionArn,
+                  eventSourceList.ScheduleEvents,
+                  (err, results) => {
+                    if (err) return reject(err)
+                    resolve(results)
+                  }
+                )
+              })
+            ]).then((results) => {
+              cb(null, results)
+            }).catch((err) => {
+              cb(err)
             })
           })
         }
@@ -843,30 +859,48 @@ Lambda.prototype.deploy = function (program) {
         // Function exists
         _this._listEventSourceMappings(lambda, {
           'FunctionName': params.FunctionName
-        }, function (err, existingEventSourceList) {
+        }, (err, existingEventSourceList) => {
           if (err) {
             throw err
           }
-          return async.parallel([
-            function (_callback) {
-              _this._uploadExisting(lambda, params, function (err, results) {
+
+          // This code is on its way to Promise.
+          // From now on, callback will not be used.
+          return Promise.all([
+            new Promise((resolve, reject) => {
+              _this._uploadExisting(lambda, params, (err, results) => {
                 if (err) {
                   throw err
                 }
                 console.log('=> Zip file(s) done uploading. Results follow: ')
                 console.log(results)
-                _this._updateScheduleEvents(scheduleEvents, results.FunctionArn, eventSourceList.ScheduleEvents, function (err, results) {
-                  _callback(err, results)
-                })
-              })
-            },
-            function (_callback) {
-              _this._updateEventSources(lambda, params.FunctionName, existingEventSourceList, eventSourceList.EventSourceMappings, function (err, results) {
-                _callback(err, results)
+                _this._updateScheduleEvents(
+                  scheduleEvents,
+                  results.FunctionArn,
+                  eventSourceList.ScheduleEvents,
+                  (err, results) => {
+                    if (err) return reject(err)
+                    resolve(results)
+                  }
+                )
               })
-            }
-          ], function (err, results) {
-            cb(err, results)
+            }),
+            new Promise((resolve, reject) => {
+              _this._updateEventSources(
+                lambda,
+                params.FunctionName,
+                existingEventSourceList,
+                eventSourceList.EventSourceMappings,
+                (err, results) => {
+                  if (err) return reject(err)
+                  resolve(results)
+                }
+              )
+            })
+          ]).then((results) => {
+            cb(null, results)
+          }).catch((err) => {
+            cb(err)
           })
         })
       })
diff --git a/test/main.js b/test/main.js
index 985932d3..5cc0518a 100644
--- a/test/main.js
+++ b/test/main.js
@@ -7,6 +7,7 @@ const lambda = require(path.join(__dirname, '..', 'lib', 'main'))
 const Zip = require('node-zip')
 const assert = require('chai').assert
 const awsMock = require('aws-sdk-mock')
+awsMock.setSDK(path.resolve('node_modules/aws-sdk'))
 
 const originalProgram = {
   environment: 'development',