diff --git a/package.json b/package.json
index a68db61..9173e98 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,6 @@
     "antd": "^3.13.2",
     "crypto-js": "^3.1.9-1",
     "file-saver": "^2.0.0",
-    "file-to-array-buffer": "^1.0.0",
     "jszip": "^3.1.5",
     "react": "^16.8.2",
     "react-app-rewired": "^2.1.0",
@@ -37,4 +36,4 @@
     "not op_mini all"
   ],
   "devDependencies": {}
-}
+}
\ No newline at end of file
diff --git a/src/worker/handleFiles.js b/src/worker/handleFiles.js
index 09010b5..7c90056 100644
--- a/src/worker/handleFiles.js
+++ b/src/worker/handleFiles.js
@@ -1,10 +1,10 @@
 import JSZip from "jszip";
 import CryptoJS from "crypto-js";
-import fileToArrayBuffer from "file-to-array-buffer";
 import {
     b64toBlob,
     base64ArrayBuffer,
-    asyncForEach
+    asyncForEach,
+    fileToArrayBuffer
 } from "./utils";
 
 export const getSHA256 = async (value) => {
diff --git a/src/worker/utils.js b/src/worker/utils.js
index e008374..7e27371 100644
--- a/src/worker/utils.js
+++ b/src/worker/utils.js
@@ -24,6 +24,21 @@ export function b64toBlob(b64Data, contentType, sliceSize) {
     return blob;
 }
 
+export function fileToArrayBuffer(file) {
+    return new Promise(function (resolve, reject) {
+        const reader = new FileReader()
+
+        reader.onerror = function onerror(ev) {
+            reject(ev.target.error)
+        }
+
+        reader.onload = function onload(ev) {
+            resolve(ev.target.result)
+        }
+
+        reader.readAsArrayBuffer(file)
+    })
+}
 
 export function base64ArrayBuffer(arrayBuffer) {
     var base64 = "";