diff --git a/external/builder/test-fixtures.js b/external/builder/test-fixtures.js
index 90b501879..65ea532dc 100644
--- a/external/builder/test-fixtures.js
+++ b/external/builder/test-fixtures.js
@@ -21,7 +21,7 @@ files.forEach(function (expectationFilename) {
     .readFileSync(expectationFilename)
     .toString()
     .trim()
-    .replace(/__filename/g, fs.realpathSync(inFilename));
+    .replaceAll("__filename", fs.realpathSync(inFilename));
   const outLines = [];
 
   const outFilename = function (line) {
diff --git a/external/builder/test-fixtures_esprima.js b/external/builder/test-fixtures_esprima.js
index 35128aee5..947b4cf6c 100644
--- a/external/builder/test-fixtures_esprima.js
+++ b/external/builder/test-fixtures_esprima.js
@@ -21,7 +21,7 @@ files.forEach(function (expectationFilename) {
     .readFileSync(expectationFilename)
     .toString()
     .trim()
-    .replace(/__filename/g, fs.realpathSync(inFilename));
+    .replaceAll("__filename", fs.realpathSync(inFilename));
   const input = fs.readFileSync(inFilename).toString();
 
   const defines = {
diff --git a/external/importL10n/locales.js b/external/importL10n/locales.js
index bc10a284e..798fd715b 100644
--- a/external/importL10n/locales.js
+++ b/external/importL10n/locales.js
@@ -27,7 +27,7 @@ const DEFAULT_LOCALE = "en-US";
 const EXCLUDE_LANG_CODES = ["ca-valencia", "ja-JP-mac"];
 
 function normalizeText(s) {
-  return s.replace(/\r\n?/g, "\n").replace(/\uFEFF/g, "");
+  return s.replace(/\r\n?/g, "\n").replaceAll("\uFEFF", "");
 }
 
 function downloadLanguageCodes() {
diff --git a/src/core/catalog.js b/src/core/catalog.js
index 2dff6d2d0..6cb33baa3 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -989,7 +989,7 @@ class Catalog {
       if (javaScript === null) {
         javaScript = new Map();
       }
-      js = stringToPDFString(js).replace(/\u0000/g, "");
+      js = stringToPDFString(js).replaceAll("\x00", "");
       javaScript.set(name, js);
     }
 
diff --git a/src/core/core_utils.js b/src/core/core_utils.js
index f4541dabe..e721dd980 100644
--- a/src/core/core_utils.js
+++ b/src/core/core_utils.js
@@ -341,7 +341,7 @@ function _collectJS(entry, xref, list, parents) {
       } else if (typeof js === "string") {
         code = js;
       }
-      code = code && stringToPDFString(code).replace(/\u0000/g, "");
+      code = code && stringToPDFString(code).replaceAll("\x00", "");
       if (code) {
         list.push(code);
       }
diff --git a/src/core/file_spec.js b/src/core/file_spec.js
index 3eb1c5a7d..da85e9046 100644
--- a/src/core/file_spec.js
+++ b/src/core/file_spec.js
@@ -68,9 +68,9 @@ class FileSpec {
     if (!this._filename && this.root) {
       const filename = pickPlatformItem(this.root) || "unnamed";
       this._filename = stringToPDFString(filename)
-        .replace(/\\\\/g, "\\")
-        .replace(/\\\//g, "/")
-        .replace(/\\/g, "/");
+        .replaceAll("\\\\", "\\")
+        .replaceAll("\\/", "/")
+        .replaceAll("\\", "/");
     }
     return this._filename;
   }
diff --git a/src/display/content_disposition.js b/src/display/content_disposition.js
index 0e9ddd11b..787d848d1 100644
--- a/src/display/content_disposition.js
+++ b/src/display/content_disposition.js
@@ -199,7 +199,7 @@ function getFilenameFromContentDispositionHeader(contentDisposition) {
       function (matches, charset, encoding, text) {
         if (encoding === "q" || encoding === "Q") {
           // RFC 2047 section 4.2.
-          text = text.replace(/_/g, " ");
+          text = text.replaceAll("_", " ");
           text = text.replace(/=([0-9a-fA-F]{2})/g, function (match, hex) {
             return String.fromCharCode(parseInt(hex, 16));
           });
diff --git a/test/unit/ui_utils_spec.js b/test/unit/ui_utils_spec.js
index 704008175..4935489f7 100644
--- a/test/unit/ui_utils_spec.js
+++ b/test/unit/ui_utils_spec.js
@@ -157,9 +157,10 @@ describe("ui_utils", function () {
     });
 
     it("should modify string with non-displayable characters", function () {
-      const str = Array.from(Array(32).keys())
-        .map(x => String.fromCharCode(x) + "a")
-        .join("");
+      const str = Array.from(
+        Array(32).keys(),
+        x => String.fromCharCode(x) + "a"
+      ).join("");
       // \x00 is replaced by an empty string.
       const expected =
         "a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a";
diff --git a/web/pdf_link_service.js b/web/pdf_link_service.js
index de8172e6b..249dce587 100644
--- a/web/pdf_link_service.js
+++ b/web/pdf_link_service.js
@@ -352,7 +352,7 @@ class PDFLinkService {
       if (params.has("search")) {
         this.eventBus.dispatch("findfromurlhash", {
           source: this,
-          query: params.get("search").replace(/"/g, ""),
+          query: params.get("search").replaceAll('"', ""),
           phraseSearch: params.get("phrase") === "true",
         });
       }
diff --git a/web/ui_utils.js b/web/ui_utils.js
index 82c57c790..59574db85 100644
--- a/web/ui_utils.js
+++ b/web/ui_utils.js
@@ -211,7 +211,6 @@ function parseQueryString(query) {
   return params;
 }
 
-const NullCharactersRegExp = /\x00/g;
 const InvisibleCharactersRegExp = /[\x01-\x1F]/g;
 
 /**
@@ -226,7 +225,7 @@ function removeNullCharacters(str, replaceInvisible = false) {
   if (replaceInvisible) {
     str = str.replace(InvisibleCharactersRegExp, " ");
   }
-  return str.replace(NullCharactersRegExp, "");
+  return str.replaceAll("\x00", "");
 }
 
 /**