diff --git a/app/extensions/pdfjs/content/build/pdf.js b/app/extensions/pdfjs/content/build/pdf.js
index cbd2db61050..4508b632684 100644
--- a/app/extensions/pdfjs/content/build/pdf.js
+++ b/app/extensions/pdfjs/content/build/pdf.js
@@ -28,8 +28,8 @@ factory((root.pdfjsDistBuildPdf = {}));
   // Use strict in our context only - users might not want it
   'use strict';
 
-var pdfjsVersion = '1.5.361';
-var pdfjsBuild = '452c06e';
+var pdfjsVersion = '1.5.364';
+var pdfjsBuild = '81cd66c';
 
   var pdfjsFilePath =
     typeof document !== 'undefined' && document.currentScript ?
diff --git a/app/extensions/pdfjs/content/build/pdf.worker.js b/app/extensions/pdfjs/content/build/pdf.worker.js
index 6144683a77a..3680686b44b 100644
--- a/app/extensions/pdfjs/content/build/pdf.worker.js
+++ b/app/extensions/pdfjs/content/build/pdf.worker.js
@@ -28,8 +28,8 @@ factory((root.pdfjsDistBuildPdfWorker = {}));
   // Use strict in our context only - users might not want it
   'use strict';
 
-var pdfjsVersion = '1.5.361';
-var pdfjsBuild = '452c06e';
+var pdfjsVersion = '1.5.364';
+var pdfjsBuild = '81cd66c';
 
   var pdfjsFilePath =
     typeof document !== 'undefined' && document.currentScript ?
diff --git a/app/extensions/pdfjs/content/web/viewer.js b/app/extensions/pdfjs/content/web/viewer.js
index 7d05e518db0..bb45628ae54 100644
--- a/app/extensions/pdfjs/content/web/viewer.js
+++ b/app/extensions/pdfjs/content/web/viewer.js
@@ -9403,7 +9403,7 @@ exports.DefaultExernalServices = DefaultExernalServices;
   }
 
   function isAllowedFileSchemeAccess(callback) {
-    callback(true)
+    callback(true);
   }
 
   function isRuntimeAvailable() {
diff --git a/app/extensions/pdfjs/feature-detect.js b/app/extensions/pdfjs/feature-detect.js
index 65b24467812..b6d5ad9699f 100644
--- a/app/extensions/pdfjs/feature-detect.js
+++ b/app/extensions/pdfjs/feature-detect.js
@@ -18,109 +18,9 @@ limitations under the License.
 'use strict';
 
 var Features = {
-  featureDetectLastUA: '',
+  featureDetectLastUA: navigator.userAgent,
   // Whether ftp: in XMLHttpRequest is allowed
   extensionSupportsFTP: false,
   // Whether redirectUrl at onHeadersReceived is supported.
-  webRequestRedirectUrl: false,
+  webRequestRedirectUrl: true,
 };
-
-chrome.storage.local.get(Features, function(features) {
-  Features = features;
-  if (features.featureDetectLastUA === navigator.userAgent) {
-    // Browser not upgraded, so the features did probably not change.
-    return;
-  }
-
-  // In case of a downgrade, the features must be tested again.
-  var lastVersion = /Chrome\/\d+\.0\.(\d+)/.exec(features.featureDetectLastUA);
-  lastVersion = lastVersion ? parseInt(lastVersion[1], 10) : 0;
-  var newVersion = /Chrome\/\d+\.0\.(\d+)/.exec(navigator.userAgent);
-  var isDowngrade = newVersion && parseInt(newVersion[1], 10) < lastVersion;
-
-  var inconclusiveTestCount = 0;
-
-  if (isDowngrade || !features.extensionSupportsFTP) {
-    features.extensionSupportsFTP = featureTestFTP();
-  }
-
-  if (isDowngrade || !features.webRequestRedirectUrl) {
-    ++inconclusiveTestCount;
-    // Relatively expensive (and asynchronous) test:
-    featureTestRedirectOnHeadersReceived(function(result) {
-      // result = 'yes', 'no' or 'maybe'.
-      if (result !== 'maybe') {
-        --inconclusiveTestCount;
-      }
-      features.webRequestRedirectUrl = result === 'yes';
-      checkTestCompletion();
-    });
-  }
-
-  checkTestCompletion();
-
-  function checkTestCompletion() {
-    // Only stamp the feature detection results when all tests have finished.
-    if (inconclusiveTestCount === 0) {
-      Features.featureDetectLastUA = navigator.userAgent;
-    }
-    chrome.storage.local.set(Features);
-  }
-});
-
-// Tests whether the extension can perform a FTP request.
-// Feature is supported since Chromium 35.0.1888.0 (r256810).
-function featureTestFTP() {
-  var x = new XMLHttpRequest();
-  // The URL does not need to exist, as long as the scheme is ftp:.
-  x.open('GET', 'ftp://ftp.mozilla.org/');
-  try {
-    x.send();
-    // Previous call did not throw error, so the feature is supported!
-    // Immediately abort the request so that the network is not hit at all.
-    x.abort();
-    return true;
-  } catch (e) {
-    return false;
-  }
-}
-
-// Tests whether redirectUrl at the onHeadersReceived stage is functional.
-// Feature is supported since Chromium 35.0.1911.0 (r259546).
-function featureTestRedirectOnHeadersReceived(callback) {
-  // The following URL is really going to be accessed via the network.
-  // It is the only way to feature-detect this feature, because the
-  // onHeadersReceived event is only triggered for http(s) requests.
-  var url = 'http://example.com/?feature-detect-' + chrome.runtime.id;
-  function onHeadersReceived(details) {
-    // If supported, the request is redirected.
-    // If not supported, the return value is ignored.
-    return {
-      redirectUrl: chrome.runtime.getURL('/manifest.json')
-    };
-  }
-  chrome.webRequest.onHeadersReceived.addListener(onHeadersReceived, {
-    types: ['xmlhttprequest'],
-    urls: [url]
-  }, ['blocking']);
-
-  var x = new XMLHttpRequest();
-  x.open('get', url);
-  x.onloadend = function() {
-    chrome.webRequest.onHeadersReceived.removeListener(onHeadersReceived);
-    if (!x.responseText) {
-      // Network error? Anyway, can't tell with certainty whether the feature
-      // is supported.
-      callback('maybe');
-    } else if (/^\s*\{/.test(x.responseText)) {
-      // If the response starts with "{", assume that the redirection to the
-      // manifest file succeeded, so the feature is supported.
-      callback('yes');
-    } else {
-      // Did not get the content of manifest.json, so the redirect seems not to
-      // be followed. The feature is not supported.
-      callback('no');
-    }
-  };
-  x.send();
-}
diff --git a/app/extensions/pdfjs/manifest.json b/app/extensions/pdfjs/manifest.json
index 2a1174ef16f..1b0cbbe1844 100644
--- a/app/extensions/pdfjs/manifest.json
+++ b/app/extensions/pdfjs/manifest.json
@@ -1,7 +1,7 @@
 {
   "manifest_version": 2,
   "name": "PDF Viewer",
-  "version": "1.5.361",
+  "version": "1.5.364",
   "description": "Uses HTML5 to display PDF files directly in the browser.",
   "icons": {
     "128": "icon128.png",
@@ -39,11 +39,6 @@
   "storage": {
     "managed_schema": "preferences_schema.json"
   },
-  "options_ui": {
-    "page": "options/options.html",
-    "chrome_style": true
-  },
-  "options_page": "options/options.html",
   "background": {
     "page": "pdfHandler.html"
   },