diff --git a/src/display/api.js b/src/display/api.js
index 5f6de4de7..fda92f75e 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -166,7 +166,7 @@ if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("PRODUCTION")) {
  * @property {string} [cMapUrl] - The URL where the predefined Adobe CMaps are
  *   located. Include the trailing slash.
  * @property {boolean} [cMapPacked] - Specifies if the Adobe CMaps are binary
- *   packed or not.
+ *   packed or not. The default value is `true`.
  * @property {Object} [CMapReaderFactory] - The factory that will be used when
  *   reading built-in CMap files. Providing a custom factory is useful for
  *   environments without Fetch API or `XMLHttpRequest` support, such as
@@ -347,6 +347,7 @@ function getDocument(src) {
     params[key] = val;
   }
 
+  params.cMapPacked = params.cMapPacked !== false;
   params.CMapReaderFactory =
     params.CMapReaderFactory || DefaultCMapReaderFactory;
   params.StandardFontDataFactory =
diff --git a/src/display/base_factory.js b/src/display/base_factory.js
index a9e4a242c..148b978fd 100644
--- a/src/display/base_factory.js
+++ b/src/display/base_factory.js
@@ -65,7 +65,7 @@ class BaseCanvasFactory {
 }
 
 class BaseCMapReaderFactory {
-  constructor({ baseUrl = null, isCompressed = false }) {
+  constructor({ baseUrl = null, isCompressed = true }) {
     if (this.constructor === BaseCMapReaderFactory) {
       unreachable("Cannot initialize BaseCMapReaderFactory.");
     }
diff --git a/test/driver.js b/test/driver.js
index 746540b2c..fc6f092ce 100644
--- a/test/driver.js
+++ b/test/driver.js
@@ -30,7 +30,6 @@ const { GenericL10n, NullL10n, parseQueryString, SimpleLinkService } =
 
 const WAITING_TIME = 100; // ms
 const CMAP_URL = "/build/generic/web/cmaps/";
-const CMAP_PACKED = true;
 const STANDARD_FONT_DATA_URL = "/build/generic/web/standard_fonts/";
 const IMAGE_RESOURCES_PATH = "/web/images/";
 const VIEWER_CSS = "../build/components/pdf_viewer.css";
@@ -475,7 +474,6 @@ class Driver {
           url: absoluteUrl,
           password: task.password,
           cMapUrl: CMAP_URL,
-          cMapPacked: CMAP_PACKED,
           standardFontDataUrl: STANDARD_FONT_DATA_URL,
           disableRange: task.disableRange,
           disableAutoFetch: !task.enableAutoFetch,
diff --git a/test/unit/annotation_spec.js b/test/unit/annotation_spec.js
index 0b5bf1726..fa860b3d6 100644
--- a/test/unit/annotation_spec.js
+++ b/test/unit/annotation_spec.js
@@ -32,7 +32,7 @@ import {
   stringToUTF8String,
 } from "../../src/shared/util.js";
 import {
-  CMAP_PARAMS,
+  CMAP_URL,
   createIdFactory,
   STANDARD_FONT_DATA_URL,
   XRefMock,
@@ -108,8 +108,7 @@ describe("annotation", function () {
     });
 
     const CMapReaderFactory = new DefaultCMapReaderFactory({
-      baseUrl: CMAP_PARAMS.cMapUrl,
-      isCompressed: CMAP_PARAMS.cMapPacked,
+      baseUrl: CMAP_URL,
     });
 
     const builtInCMapCache = new Map();
diff --git a/test/unit/cmap_spec.js b/test/unit/cmap_spec.js
index 2fd77d30d..b1dbdccc9 100644
--- a/test/unit/cmap_spec.js
+++ b/test/unit/cmap_spec.js
@@ -14,7 +14,7 @@
  */
 
 import { CMap, CMapFactory, IdentityCMap } from "../../src/core/cmap.js";
-import { CMAP_PARAMS } from "./test_utils.js";
+import { CMAP_URL } from "./test_utils.js";
 import { DefaultCMapReaderFactory } from "../../src/display/api.js";
 import { Name } from "../../src/core/primitives.js";
 import { StringStream } from "../../src/core/stream.js";
@@ -25,8 +25,7 @@ describe("cmap", function () {
   beforeAll(function () {
     // Allow CMap testing in Node.js, e.g. for Travis.
     const CMapReaderFactory = new DefaultCMapReaderFactory({
-      baseUrl: CMAP_PARAMS.cMapUrl,
-      isCompressed: CMAP_PARAMS.cMapPacked,
+      baseUrl: CMAP_URL,
     });
 
     fetchBuiltInCMap = function (name) {
@@ -232,7 +231,7 @@ describe("cmap", function () {
   it("attempts to load a built-in CMap with inconsistent API parameters", async function () {
     function tmpFetchBuiltInCMap(name) {
       const CMapReaderFactory = new DefaultCMapReaderFactory({
-        baseUrl: CMAP_PARAMS.cMapUrl,
+        baseUrl: CMAP_URL,
         isCompressed: false,
       });
       return CMapReaderFactory.fetch({ name });
diff --git a/test/unit/pdf_find_controller_spec.js b/test/unit/pdf_find_controller_spec.js
index 719f895e0..7326f17b7 100644
--- a/test/unit/pdf_find_controller_spec.js
+++ b/test/unit/pdf_find_controller_spec.js
@@ -21,10 +21,8 @@ import { isNodeJS } from "../../src/shared/is_node.js";
 import { SimpleLinkService } from "../../web/pdf_link_service.js";
 
 const tracemonkeyFileName = "tracemonkey.pdf";
-const CMAP_PARAMS = {
-  cMapUrl: isNodeJS ? "./external/bcmaps/" : "../../../external/bcmaps/",
-  cMapPacked: true,
-};
+
+const CMAP_URL = isNodeJS ? "./external/bcmaps/" : "../../../external/bcmaps/";
 
 class MockLinkService extends SimpleLinkService {
   constructor() {
@@ -57,7 +55,7 @@ async function initPdfFindController(
 ) {
   const loadingTask = getDocument(
     buildGetDocumentParams(filename || tracemonkeyFileName, {
-      ...CMAP_PARAMS,
+      cMapUrl: CMAP_URL,
     })
   );
   const pdfDocument = await loadingTask.promise;
diff --git a/test/unit/test_utils.js b/test/unit/test_utils.js
index 846c2b6c8..dd52a9275 100644
--- a/test/unit/test_utils.js
+++ b/test/unit/test_utils.js
@@ -21,10 +21,7 @@ import { Ref } from "../../src/core/primitives.js";
 
 const TEST_PDFS_PATH = isNodeJS ? "./test/pdfs/" : "../pdfs/";
 
-const CMAP_PARAMS = {
-  cMapUrl: isNodeJS ? "./external/bcmaps/" : "../../external/bcmaps/",
-  cMapPacked: true,
-};
+const CMAP_URL = isNodeJS ? "./external/bcmaps/" : "../../external/bcmaps/";
 
 const STANDARD_FONT_DATA_URL = isNodeJS
   ? "./external/standard_fonts/"
@@ -154,7 +151,7 @@ function isEmptyObj(obj) {
 
 export {
   buildGetDocumentParams,
-  CMAP_PARAMS,
+  CMAP_URL,
   createIdFactory,
   DefaultFileReaderFactory,
   isEmptyObj,