diff --git a/src/shared/compatibility.js b/src/shared/compatibility.js
index a12e93bda..57d9c47c7 100644
--- a/src/shared/compatibility.js
+++ b/src/shared/compatibility.js
@@ -18,10 +18,16 @@
 // Skip compatibility checks for the extensions and if we already ran
 // this module.
 if ((typeof PDFJSDev === 'undefined' ||
-     !PDFJSDev.test('FIREFOX || MOZCENTRAL || CHROME')) &&
+     !PDFJSDev.test('FIREFOX || MOZCENTRAL')) &&
     (typeof PDFJS === 'undefined' || !PDFJS.compatibilityChecked)) {
 
+// In the Chrome extension, most of the polyfills are unnecessary.
+// We support down to Chrome 49, because it's still commonly used by Windows XP
+// users - https://github.com/mozilla/pdf.js/issues/9397
+if (typeof PDFJSDev === 'undefined' || !PDFJSDev.test('CHROME')) {
+
 var globalScope = require('./global_scope');
+
 const isNodeJS = require('./is_node');
 
 var userAgent = (typeof navigator !== 'undefined' && navigator.userAgent) || '';
@@ -151,15 +157,6 @@ PDFJS.compatibilityChecked = true;
   };
 })();
 
-// Provides support for Object.values in legacy browsers.
-// Support: IE, Chrome<54
-(function checkObjectValues() {
-  if (Object.values) {
-    return;
-  }
-  Object.values = require('core-js/fn/object/values');
-})();
-
 // Provides support for Array.prototype.includes in legacy browsers.
 // Support: IE, Chrome<47
 (function checkArrayIncludes() {
@@ -865,4 +862,15 @@ PDFJS.compatibilityChecked = true;
   globalScope.URL = JURL;
 })();
 
+} // End of !PDFJSDev.test('CHROME')
+
+// Provides support for Object.values in legacy browsers.
+// Support: IE, Chrome<54
+(function checkObjectValues() {
+  if (Object.values) {
+    return;
+  }
+  Object.values = require('core-js/fn/object/values');
+})();
+
 }
diff --git a/src/shared/streams_polyfill.js b/src/shared/streams_polyfill.js
index e35da6cd9..7c8e85d87 100644
--- a/src/shared/streams_polyfill.js
+++ b/src/shared/streams_polyfill.js
@@ -31,9 +31,6 @@ if (typeof ReadableStream !== 'undefined') {
 if (isReadableStreamSupported) {
   exports.ReadableStream = ReadableStream;
 } else {
-  if (typeof PDFJSDev !== 'undefined' && PDFJSDev.test('CHROME')) {
-    throw new Error('ReadableStream polyfill is not found for Chrome bundle');
-  }
   exports.ReadableStream =
     require('../../external/streams/streams-lib').ReadableStream;
 }