1 files changed, 3 insertions, 1 deletions
diff --git a/ext/js/pages/settings/popup-window-controller.js b/ext/js/pages/settings/popup-window-controller.js
index e1a5456b..0d56dc58 100644
--- a/ext/js/pages/settings/popup-window-controller.js
+++ b/ext/js/pages/settings/popup-window-controller.js
@@ -16,12 +16,14 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+import {querySelectorNotNull} from '../../dom/query-selector.js';
 import {yomitan} from '../../yomitan.js';
 
 export class PopupWindowController {
     /** */
     prepare() {
-        const testLink = /** @type {HTMLElement} */ (document.querySelector('#test-window-open-link'));
+        /** @type {HTMLElement} */
+        const testLink = querySelectorNotNull(document, '#test-window-open-link');
         testLink.addEventListener('click', this._onTestWindowOpenLinkClick.bind(this), false);
     }