diff --git a/src/post-worker.js b/src/post-worker.js
index 13675a89..6c01f39a 100644
--- a/src/post-worker.js
+++ b/src/post-worker.js
@@ -594,6 +594,7 @@ function onMessageFromMainEmscriptenThread(message) {
             for (var i = 0; i < self.octObj.getEventCount(); i++) {
                 var evnt_ptr = self.octObj.track.get_events(i);
                 var event = {
+                    _index: i,
                     Start: evnt_ptr.get_Start(),
                     Duration: evnt_ptr.get_Duration(),
                     ReadOrder: evnt_ptr.get_ReadOrder(),
@@ -636,6 +637,7 @@ function onMessageFromMainEmscriptenThread(message) {
             for (var i = 0; i < self.octObj.getStyleCount(); i++) {
                 var styl_ptr = self.octObj.track.get_styles(i);
                 var style = {
+                    _index: i,
                     Name: styl_ptr.get_Name(),
                     FontName: styl_ptr.get_FontName(),
                     FontSize: styl_ptr.get_FontSize(),
diff --git a/src/subtitles-octopus.js b/src/subtitles-octopus.js
index 0418f8b8..9ef440e9 100644
--- a/src/subtitles-octopus.js
+++ b/src/subtitles-octopus.js
@@ -88,8 +88,8 @@ var SubtitlesOctopus = function (options) {
         // Worker
         if (!self.worker) {
             self.worker = new Worker(self.workerUrl);
-            self.worker.onmessage = self.onWorkerMessage;
-            self.worker.onerror = self.workerError;
+            self.worker.addEventListener('message', self.onWorkerMessage);
+            self.worker.addEventListener('error', self.workerError);
         }
         self.workerActive = false;
         self.createCanvas();
@@ -387,13 +387,9 @@ var SubtitlesOctopus = function (options) {
                 break;
             }
             case 'get-events': {
-                console.log(data.target);
-                console.log(data.events);
                 break;
             }
             case 'get-styles': {
-                console.log(data.target);
-                console.log(data.styles);
                 break;
             }
             case 'ready': {
@@ -538,8 +534,24 @@ var SubtitlesOctopus = function (options) {
     };
 
     self.getEvents = function () {
-        self.worker.postMessage({
-            target: 'get-events'
+        return new Promise((resolve, reject) => {
+            try {
+                self.worker.onmessage = result => {
+                    if (result.data.target == "get-events") {
+                        resolve(result.data.events);
+                    }
+                };
+            
+                self.worker.onerror = error => {
+                    reject(error);
+                };
+
+                self.worker.postMessage({
+                    target: 'get-events'
+                });
+            } catch (error) {
+                reject(error);
+            }
         });
     };
 
@@ -566,8 +578,24 @@ var SubtitlesOctopus = function (options) {
     };
 
     self.getStyles = function () {
-        self.worker.postMessage({
-            target: 'get-styles'
+        return new Promise((resolve, reject) => {
+            try {
+                self.worker.onmessage = result => {
+                    if (result.data.target == "get-styles") {
+                        resolve(result.data.styles);
+                    }
+                };
+            
+                self.worker.onerror = error => {
+                    reject(error);
+                };
+
+                self.worker.postMessage({
+                    target: 'get-styles'
+                });
+            } catch (error) {
+                reject(error);
+            }
         });
     };