diff --git a/web/app.js b/web/app.js
index 8c605a20ae12b..822cf4fbd06d3 100644
--- a/web/app.js
+++ b/web/app.js
@@ -286,7 +286,7 @@ let PDFViewerApplication = {
     this.overlayManager = new OverlayManager();
 
     const dispatchToDOM = AppOptions.get('eventBusDispatchToDOM');
-    let eventBus = appConfig.eventBus || getGlobalEventBus(dispatchToDOM);
+    const eventBus = appConfig.eventBus || getGlobalEventBus(dispatchToDOM);
     this.eventBus = eventBus;
 
     let pdfRenderingQueue = new PDFRenderingQueue();
@@ -349,10 +349,7 @@ let PDFViewerApplication = {
     });
     pdfLinkService.setHistory(this.pdfHistory);
 
-    // TODO: improve `PDFFindBar` constructor parameter passing
-    let findBarConfig = Object.create(appConfig.findBar);
-    findBarConfig.eventBus = eventBus;
-    this.findBar = new PDFFindBar(findBarConfig, this.l10n);
+    this.findBar = new PDFFindBar(appConfig.findBar, eventBus, this.l10n);
 
     this.pdfDocumentProperties =
       new PDFDocumentProperties(appConfig.documentProperties,
@@ -399,9 +396,7 @@ let PDFViewerApplication = {
     let sidebarConfig = Object.create(appConfig.sidebar);
     sidebarConfig.pdfViewer = this.pdfViewer;
     sidebarConfig.pdfThumbnailViewer = this.pdfThumbnailViewer;
-    sidebarConfig.pdfOutlineViewer = this.pdfOutlineViewer;
-    sidebarConfig.eventBus = eventBus;
-    this.pdfSidebar = new PDFSidebar(sidebarConfig, this.l10n);
+    this.pdfSidebar = new PDFSidebar(sidebarConfig, eventBus, this.l10n);
     this.pdfSidebar.onToggled = this.forceRendering.bind(this);
 
     this.pdfSidebarResizer = new PDFSidebarResizer(appConfig.sidebarResizer,
diff --git a/web/pdf_find_bar.js b/web/pdf_find_bar.js
index b1696b5c92f9f..e3becbd67cd99 100644
--- a/web/pdf_find_bar.js
+++ b/web/pdf_find_bar.js
@@ -13,8 +13,8 @@
  * limitations under the License.
  */
 
+import { getGlobalEventBus, NullL10n } from './ui_utils';
 import { FindState } from './pdf_find_controller';
-import { NullL10n } from './ui_utils';
 
 const MATCHES_COUNT_LIMIT = 1000;
 
@@ -25,7 +25,7 @@ const MATCHES_COUNT_LIMIT = 1000;
  * is done by PDFFindController.
  */
 class PDFFindBar {
-  constructor(options, l10n = NullL10n) {
+  constructor(options, eventBus = getGlobalEventBus(), l10n = NullL10n) {
     this.opened = false;
 
     this.bar = options.bar || null;
@@ -38,7 +38,7 @@ class PDFFindBar {
     this.findResultsCount = options.findResultsCount || null;
     this.findPreviousButton = options.findPreviousButton || null;
     this.findNextButton = options.findNextButton || null;
-    this.eventBus = options.eventBus;
+    this.eventBus = eventBus;
     this.l10n = l10n;
 
     // Add event listeners to the DOM elements.
diff --git a/web/pdf_outline_viewer.js b/web/pdf_outline_viewer.js
index 6a30b1ebde492..bc02795185be4 100644
--- a/web/pdf_outline_viewer.js
+++ b/web/pdf_outline_viewer.js
@@ -39,6 +39,8 @@ class PDFOutlineViewer {
     this.eventBus = eventBus;
 
     this.reset();
+
+    eventBus.on('toggleoutlinetree', this.toggleOutlineTree.bind(this));
   }
 
   reset() {
diff --git a/web/pdf_sidebar.js b/web/pdf_sidebar.js
index d984a3d347e66..27a77ad59b11b 100644
--- a/web/pdf_sidebar.js
+++ b/web/pdf_sidebar.js
@@ -29,12 +29,10 @@ const SidebarView = {
  * @typedef {Object} PDFSidebarOptions
  * @property {PDFViewer} pdfViewer - The document viewer.
  * @property {PDFThumbnailViewer} pdfThumbnailViewer - The thumbnail viewer.
- * @property {PDFOutlineViewer} pdfOutlineViewer - The outline viewer.
  * @property {HTMLDivElement} outerContainer - The outer container
  *   (encasing both the viewer and sidebar elements).
  * @property {HTMLDivElement} viewerContainer - The viewer container
  *   (in which the viewer element is placed).
- * @property {EventBus} eventBus - The application event bus.
  * @property {HTMLButtonElement} toggleButton - The button used for
  *   opening/closing the sidebar.
  * @property {HTMLButtonElement} thumbnailButton - The button used to show
@@ -56,9 +54,10 @@ const SidebarView = {
 class PDFSidebar {
   /**
    * @param {PDFSidebarOptions} options
+   * @param {EventBus} eventBus - The application event bus.
    * @param {IL10n} l10n - Localization service.
    */
-  constructor(options, l10n = NullL10n) {
+  constructor(options, eventBus, l10n = NullL10n) {
     this.isOpen = false;
     this.active = SidebarView.THUMBS;
     this.isInitialViewSet = false;
@@ -71,11 +70,9 @@ class PDFSidebar {
 
     this.pdfViewer = options.pdfViewer;
     this.pdfThumbnailViewer = options.pdfThumbnailViewer;
-    this.pdfOutlineViewer = options.pdfOutlineViewer;
 
     this.outerContainer = options.outerContainer;
     this.viewerContainer = options.viewerContainer;
-    this.eventBus = options.eventBus;
     this.toggleButton = options.toggleButton;
 
     this.thumbnailButton = options.thumbnailButton;
@@ -88,6 +85,7 @@ class PDFSidebar {
 
     this.disableNotification = options.disableNotification || false;
 
+    this.eventBus = eventBus;
     this.l10n = l10n;
 
     this._addEventListeners();
@@ -397,7 +395,7 @@ class PDFSidebar {
       this.switchView(SidebarView.OUTLINE);
     });
     this.outlineButton.addEventListener('dblclick', () => {
-      this.pdfOutlineViewer.toggleOutlineTree();
+      this.eventBus.dispatch('toggleoutlinetree', { source: this, });
     });
 
     this.attachmentsButton.addEventListener('click', () => {