diff --git a/web/app.js b/web/app.js
index 8c605a20a..691cd867b 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,
diff --git a/web/pdf_find_bar.js b/web/pdf_find_bar.js
index b1696b5c9..e3becbd67 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.