diff --git a/extensions/chromium/contentscript.js b/extensions/chromium/contentscript.js
index aa6edb7b3..70fa38701 100644
--- a/extensions/chromium/contentscript.js
+++ b/extensions/chromium/contentscript.js
@@ -16,7 +16,7 @@ limitations under the License.
 
 "use strict";
 
-var VIEWER_URL = chrome.extension.getURL("content/web/viewer.html");
+var VIEWER_URL = chrome.runtime.getURL("content/web/viewer.html");
 
 function getViewerURL(pdf_url) {
   return VIEWER_URL + "?file=" + encodeURIComponent(pdf_url);
diff --git a/extensions/chromium/extension-router.js b/extensions/chromium/extension-router.js
index a128a30d1..bd0cdc875 100644
--- a/extensions/chromium/extension-router.js
+++ b/extensions/chromium/extension-router.js
@@ -17,8 +17,8 @@ limitations under the License.
 "use strict";
 
 (function ExtensionRouterClosure() {
-  var VIEWER_URL = chrome.extension.getURL("content/web/viewer.html");
-  var CRX_BASE_URL = chrome.extension.getURL("/");
+  var VIEWER_URL = chrome.runtime.getURL("content/web/viewer.html");
+  var CRX_BASE_URL = chrome.runtime.getURL("/");
 
   var schemes = [
     "http",
diff --git a/extensions/chromium/pdfHandler.js b/extensions/chromium/pdfHandler.js
index b993751b0..992ec883c 100644
--- a/extensions/chromium/pdfHandler.js
+++ b/extensions/chromium/pdfHandler.js
@@ -16,7 +16,7 @@ limitations under the License.
 
 "use strict";
 
-var VIEWER_URL = chrome.extension.getURL("content/web/viewer.html");
+var VIEWER_URL = chrome.runtime.getURL("content/web/viewer.html");
 
 function getViewerURL(pdf_url) {
   // |pdf_url| may contain a fragment such as "#page=2". That should be passed