diff --git a/browser/extensions/pdfjs/README.mozilla b/browser/extensions/pdfjs/README.mozilla
index bec77ff58254..9b711d4ccf61 100644
--- a/browser/extensions/pdfjs/README.mozilla
+++ b/browser/extensions/pdfjs/README.mozilla
@@ -1,5 +1,5 @@
 This is the PDF.js project output, https://github.com/mozilla/pdf.js
 
-Current extension version is: 2.1.97
+Current extension version is: 2.1.117
 
-Taken from upstream commit: 45c01974
+Taken from upstream commit: 417c234c
diff --git a/browser/extensions/pdfjs/content/build/pdf.js b/browser/extensions/pdfjs/content/build/pdf.js
index 48a6f7aeccec..3f8fc8246663 100644
--- a/browser/extensions/pdfjs/content/build/pdf.js
+++ b/browser/extensions/pdfjs/content/build/pdf.js
@@ -123,8 +123,8 @@ return /******/ (function(modules) { // webpackBootstrap
 "use strict";
 
 
-var pdfjsVersion = '2.1.97';
-var pdfjsBuild = '45c01974';
+var pdfjsVersion = '2.1.117';
+var pdfjsBuild = '417c234c';
 
 var pdfjsSharedUtil = __w_pdfjs_require__(1);
 
@@ -5141,7 +5141,7 @@ function _fetchDocument(worker, source, pdfDataRangeTransport, docId) {
 
   return worker.messageHandler.sendWithPromise('GetDocRequest', {
     docId,
-    apiVersion: '2.1.97',
+    apiVersion: '2.1.117',
     source: {
       data: source.data,
       url: source.url,
@@ -6860,9 +6860,9 @@ const InternalRenderTask = function InternalRenderTaskClosure() {
   return InternalRenderTask;
 }();
 
-const version = '2.1.97';
+const version = '2.1.117';
 exports.version = version;
-const build = '45c01974';
+const build = '417c234c';
 exports.build = build;
 
 /***/ }),
diff --git a/browser/extensions/pdfjs/content/build/pdf.worker.js b/browser/extensions/pdfjs/content/build/pdf.worker.js
index c83f94c6382b..433d365d68fb 100644
--- a/browser/extensions/pdfjs/content/build/pdf.worker.js
+++ b/browser/extensions/pdfjs/content/build/pdf.worker.js
@@ -123,8 +123,8 @@ return /******/ (function(modules) { // webpackBootstrap
 "use strict";
 
 
-var pdfjsVersion = '2.1.97';
-var pdfjsBuild = '45c01974';
+var pdfjsVersion = '2.1.117';
+var pdfjsBuild = '417c234c';
 
 var pdfjsCoreWorker = __w_pdfjs_require__(1);
 
@@ -375,7 +375,7 @@ var WorkerMessageHandler = {
     var cancelXHRs = null;
     var WorkerTasks = [];
     let apiVersion = docParams.apiVersion;
-    let workerVersion = '2.1.97';
+    let workerVersion = '2.1.117';
 
     if (apiVersion !== workerVersion) {
       throw new Error(`The API version "${apiVersion}" does not match ` + `the Worker version "${workerVersion}".`);
@@ -22045,6 +22045,7 @@ class WidgetAnnotation extends Annotation {
     data.readOnly = this.hasFieldFlag(_util.AnnotationFieldFlag.READONLY);
 
     if (data.fieldType === 'Sig') {
+      data.fieldValue = null;
       this.setFlags(_util.AnnotationFlag.HIDDEN);
     }
   }
diff --git a/browser/extensions/pdfjs/content/web/viewer.css b/browser/extensions/pdfjs/content/web/viewer.css
index aa89a047d486..a86671cb78e4 100644
--- a/browser/extensions/pdfjs/content/web/viewer.css
+++ b/browser/extensions/pdfjs/content/web/viewer.css
@@ -1930,7 +1930,7 @@ html[dir='rtl'] #documentPropertiesOverlay .row > * {
   display: none;
 }
 
-@media screen and (min-resolution: 2dppx) {
+@media screen and (min-resolution: 1.1dppx) {
   /* Rules for Retina screens */
   .toolbarButton::before {
     transform: scale(0.5);
diff --git a/browser/extensions/pdfjs/content/web/viewer.js b/browser/extensions/pdfjs/content/web/viewer.js
index 6701ba387847..e5171ebf9ff2 100644
--- a/browser/extensions/pdfjs/content/web/viewer.js
+++ b/browser/extensions/pdfjs/content/web/viewer.js
@@ -323,6 +323,7 @@ var _view_history = __webpack_require__(32);
 const DEFAULT_SCALE_DELTA = 1.1;
 const DISABLE_AUTO_FETCH_LOADING_BAR_TIMEOUT = 5000;
 const FORCE_PAGES_LOADED_TIMEOUT = 10000;
+const WHEEL_ZOOM_DISABLED_TIMEOUT = 1000;
 const DefaultExternalServices = {
   updateFindControlState(data) {},
 
@@ -1423,6 +1424,7 @@ let PDFViewerApplication = {
       });
     };
 
+    window.addEventListener('visibilitychange', webViewerVisibilityChange);
     window.addEventListener('wheel', webViewerWheel);
     window.addEventListener('click', webViewerClick);
     window.addEventListener('keydown', webViewerKeyDown);
@@ -1482,6 +1484,7 @@ let PDFViewerApplication = {
     let {
       _boundEvents
     } = this;
+    window.removeEventListener('visibilitychange', webViewerVisibilityChange);
     window.removeEventListener('wheel', webViewerWheel);
     window.removeEventListener('click', webViewerClick);
     window.removeEventListener('keydown', webViewerKeyDown);
@@ -1917,8 +1920,23 @@ function webViewerPageChanging(evt) {
   }
 }
 
-let zoomDisabled = false,
-    zoomDisabledTimeout;
+function webViewerVisibilityChange(evt) {
+  if (document.visibilityState === 'visible') {
+    setZoomDisabledTimeout();
+  }
+}
+
+let zoomDisabledTimeout = null;
+
+function setZoomDisabledTimeout() {
+  if (zoomDisabledTimeout) {
+    clearTimeout(zoomDisabledTimeout);
+  }
+
+  zoomDisabledTimeout = setTimeout(function () {
+    zoomDisabledTimeout = null;
+  }, WHEEL_ZOOM_DISABLED_TIMEOUT);
+}
 
 function webViewerWheel(evt) {
   let pdfViewer = PDFViewerApplication.pdfViewer;
@@ -1936,7 +1954,7 @@ function webViewerWheel(evt) {
 
     evt.preventDefault();
 
-    if (zoomDisabled) {
+    if (zoomDisabledTimeout || document.visibilityState === 'hidden') {
       return;
     }
 
@@ -1962,11 +1980,7 @@ function webViewerWheel(evt) {
       pdfViewer.container.scrollTop += dy * scaleCorrectionFactor;
     }
   } else {
-    zoomDisabled = true;
-    clearTimeout(zoomDisabledTimeout);
-    zoomDisabledTimeout = setTimeout(function () {
-      zoomDisabled = false;
-    }, 1000);
+    setZoomDisabledTimeout();
   }
 }
 
@@ -2209,6 +2223,10 @@ function webViewerKeyDown(evt) {
       case 82:
         PDFViewerApplication.rotatePages(90);
         break;
+
+      case 115:
+        PDFViewerApplication.pdfSidebar.toggle();
+        break;
     }
 
     if (turnPage !== 0 && (!turnOnlyIfPageFit || pdfViewer.currentScaleValue === 'page-fit')) {
diff --git a/browser/extensions/pdfjs/moz.yaml b/browser/extensions/pdfjs/moz.yaml
index a8cf7db20591..07c1d12d4ed3 100644
--- a/browser/extensions/pdfjs/moz.yaml
+++ b/browser/extensions/pdfjs/moz.yaml
@@ -20,7 +20,7 @@ origin:
 
   # Human-readable identifier for this version/release
   # Generally "version NNN", "tag SSS", "bookmark SSS"
-  release: version 2.1.97
+  release: version 2.1.117
 
   # The package's license, where possible using the mnemonic from
   # https://spdx.org/licenses/