diff --git a/src/contentScript.js b/src/contentScript.js
index 84909373..3a83be77 100644
--- a/src/contentScript.js
+++ b/src/contentScript.js
@@ -7,6 +7,7 @@ import tippy, { sticky, hideAll } from "tippy.js";
 import { encode } from "he";
 import matchUrl from "match-url-wildcard";
 import delay from "delay";
+import browser from "webextension-polyfill";
 
 import {
   enableSelectionEndEvent,
@@ -746,7 +747,7 @@ function openPdfIframe(url) {
   $("embed").remove();
 
   $("<embed/>", {
-    src: util.getUrlExt(
+    src: browser.runtime.getURL(
       `/pdfjs/web/viewer.html?file=${encodeURIComponent(url)}`
     ),
     css: {
@@ -790,7 +791,7 @@ function injectGoogleDocAnnotation() {
     return;
   }
   var s = document.createElement("script");
-  s.src = util.getUrlExt("googleDocInject.js"); //chrome.runtime.getURL("js/docs-canvas.js");
+  s.src = browser.runtime.getURL("googleDocInject.js"); //chrome.runtime.getURL("js/docs-canvas.js");
   document.documentElement.appendChild(s);
 }
 
diff --git a/src/ocr/ocrIframe.js b/src/ocr/ocrIframe.js
index c0621712..20fd272b 100644
--- a/src/ocr/ocrIframe.js
+++ b/src/ocr/ocrIframe.js
@@ -4,8 +4,8 @@
 //3. resend result to host
 
 import Tesseract from "tesseract.js";
-
-import * as util from "/src/util";
+import { waitUntil, WAIT_FOREVER } from "async-wait-until";
+import browser from "webextension-polyfill";
 
 var schedulerList = {};
 var loadingList = {};
@@ -105,15 +105,19 @@ async function getScheduler(lang, mode) {
   if (schedulerList[id]) {
     return schedulerList[id];
   } else if (loadingList[id]) {
-    await util.waitUntilForever(() => schedulerList[id]);
+    await waitUntil(() => schedulerList[id], {
+      timeout: WAIT_FOREVER,
+    });
     return schedulerList[id];
   }
   loadingList[id] = true;
 
   var scheduler = Tesseract.createScheduler();
   var workerIndexList = mode.includes("auto") ? [0] : [0, 1, 2, 3, 4];
-  var workerPath = util.getUrlExt("/tesseract/worker.min.js");
-  var corePath = util.getUrlExt("/tesseract/tesseract-core-lstm.wasm.js");
+  var workerPath = browser.runtime.getURL("/tesseract/worker.min.js");
+  var corePath = browser.runtime.getURL(
+    "/tesseract/tesseract-core-lstm.wasm.js"
+  );
 
   var tessedit_pageseg_mode = mode.includes("auto")
     ? Tesseract.PSM.AUTO_ONLY