diff --git a/lib/schedule_events.js b/lib/schedule_events.js
index b39d51f4..1c6ac503 100644
--- a/lib/schedule_events.js
+++ b/lib/schedule_events.js
@@ -1,49 +1,48 @@
 'use strict'
 
-const ScheduleEvents = function (aws) {
-  // Authenticated `aws` object in `lib/main.js`
-  this.lambda = new aws.Lambda({
-    apiVersion: '2015-03-31'
-  })
-  this.cloudwatchevents = new aws.CloudWatchEvents({
-    apiVersion: '2015-10-07'
-  })
-}
+class ScheduleEvents {
+  constructor (aws) {
+    // Authenticated `aws` object in `lib/main.js`
+    this.lambda = new aws.Lambda({
+      apiVersion: '2015-03-31'
+    })
+    this.cloudwatchevents = new aws.CloudWatchEvents({
+      apiVersion: '2015-10-07'
+    })
+  }
 
-ScheduleEvents.prototype = {
-  _ruleDescription: (params) => {
+  _ruleDescription (params) {
     if ('ScheduleDescription' in params && params.ScheduleDescription != null) {
       return `${params.ScheduleDescription}`
     }
     return `${params.ScheduleName} - ${params.ScheduleExpression}`
-  },
+  }
 
-  _functionName: (params) => {
+  _functionName (params) {
     return params.FunctionArn.split(':').pop()
-  },
+  }
 
-  _putRulePrams: function (params) {
+  _putRulePrams (params) {
     return {
       Name: params.ScheduleName,
       Description: this._ruleDescription(params),
       State: params.ScheduleState,
       ScheduleExpression: params.ScheduleExpression
     }
-  },
+  }
 
-  _putRule: function (params) {
-    const _this = this
+  _putRule (params) {
     // return RuleArn if created
     return new Promise((resolve) => {
-      const _params = _this._putRulePrams(params)
-      _this.cloudwatchevents.putRule(_params, (err, rule) => {
+      const _params = this._putRulePrams(params)
+      this.cloudwatchevents.putRule(_params, (err, rule) => {
         if (err) throw err
         resolve(rule)
       })
     })
-  },
+  }
 
-  _addPermissionParams: function (params) {
+  _addPermissionParams (params) {
     return {
       Action: 'lambda:InvokeFunction',
       FunctionName: this._functionName(params),
@@ -51,13 +50,12 @@ ScheduleEvents.prototype = {
       SourceArn: params.RuleArn,
       StatementId: params.ScheduleName
     }
-  },
+  }
 
-  _addPermission: function (params) {
-    const _this = this
+  _addPermission (params) {
     return new Promise((resolve) => {
-      const _params = _this._addPermissionParams(params)
-      _this.lambda.addPermission(_params, (err, data) => {
+      const _params = this._addPermissionParams(params)
+      this.lambda.addPermission(_params, (err, data) => {
         if (err) {
           if (err.code !== 'ResourceConflictException') throw err
           // If it exists it will result in an error but there is no problem.
@@ -66,9 +64,9 @@ ScheduleEvents.prototype = {
         resolve(data)
       })
     })
-  },
+  }
 
-  _putTargetsParams: function (params) {
+  _putTargetsParams (params) {
     return {
       Rule: params.ScheduleName,
       Targets: [{
@@ -76,28 +74,26 @@ ScheduleEvents.prototype = {
         Id: this._functionName(params)
       }]
     }
-  },
+  }
 
-  _putTargets: function (params) {
-    const _this = this
+  _putTargets (params) {
     return new Promise((resolve) => {
-      const _params = _this._putTargetsParams(params)
-      _this.cloudwatchevents.putTargets(_params, (err, data) => {
+      const _params = this._putTargetsParams(params)
+      this.cloudwatchevents.putTargets(_params, (err, data) => {
         // even if it is already registered, it will not be an error.
         if (err) throw (err)
         resolve(data)
       })
     })
-  },
+  }
 
-  add: function (params) {
-    const _this = this
+  add (params) {
     return Promise.resolve().then(() => {
-      return _this._putRule(params)
+      return this._putRule(params)
     }).then((rule) => {
-      return _this._addPermission(Object.assign(params, rule))
+      return this._addPermission(Object.assign(params, rule))
     }).then((data) => {
-      return _this._putTargets(params)
+      return this._putTargets(params)
     })
   }
 }