diff --git a/ursh/indico_ursh/client/index.js b/ursh/indico_ursh/client/index.js
index 495c1ba..05b4b0d 100644
--- a/ursh/indico_ursh/client/index.js
+++ b/ursh/indico_ursh/client/index.js
@@ -15,6 +15,7 @@
  * along with Indico; if not, see <http://www.gnu.org/licenses/>.
  */
 
+import 'url-polyfill';
 import {handleAxiosError, indicoAxios} from 'indico/utils/axios';
 
 
@@ -41,8 +42,8 @@ function _validateAndFormatURL(url) {
     }
 
     // if protocol is missing, prepend it
-    if (url.startsWith(window.location.hostname)) {
-        url = `${window.location.protocol}//${url}`;
+    if (url.startsWith(location.hostname)) {
+        url = `${location.protocol}//${url}`;
     }
 
     let parsedURL;
diff --git a/ursh/package.json b/ursh/package.json
new file mode 100644
index 0000000..68e321b
--- /dev/null
+++ b/ursh/package.json
@@ -0,0 +1,19 @@
+{
+  "name": "indico-plugin-ursh",
+  "version": "1.0.0",
+  "description": "URL shortening service provider for Indico",
+  "main": "indico_ursh/client/index.js",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/indico/indico-plugins.git"
+  },
+  "author": "Indico Team <indico.team@cern.ch>",
+  "license": "GPL-3.0",
+  "bugs": {
+    "url": "https://github.com/indico/indico-plugins/issues"
+  },
+  "homepage": "https://github.com/indico/indico-plugins#readme",
+  "dependencies": {
+    "url-polyfill": "^1.1.0"
+  }
+}