diff --git a/tools/test-js-with-node b/tools/test-js-with-node
index 1a9d7b83a2..96085b18f0 100755
--- a/tools/test-js-with-node
+++ b/tools/test-js-with-node
@@ -78,7 +78,7 @@ EXEMPT_FILES = make_set(
         "web/src/css_variables.js",
         "web/src/dark_theme.ts",
         "web/src/debug.ts",
-        "web/src/deprecated_feature_notice.js",
+        "web/src/deprecated_feature_notice.ts",
         "web/src/desktop_integration.js",
         "web/src/dialog_widget.ts",
         "web/src/drafts.js",
diff --git a/web/src/deprecated_feature_notice.js b/web/src/deprecated_feature_notice.ts
similarity index 88%
rename from web/src/deprecated_feature_notice.js
rename to web/src/deprecated_feature_notice.ts
index ec46503f3b..b1ef69f99c 100644
--- a/web/src/deprecated_feature_notice.js
+++ b/web/src/deprecated_feature_notice.ts
@@ -6,7 +6,10 @@ import * as dialog_widget from "./dialog_widget";
 import {$t_html} from "./i18n";
 import {localstorage} from "./localstorage";
 
-export function get_hotkey_deprecation_notice(originalHotkey, replacementHotkey) {
+export function get_hotkey_deprecation_notice(
+    originalHotkey: string,
+    replacementHotkey: string,
+): string {
     return $t_html(
         {
             defaultMessage:
@@ -16,9 +19,9 @@ export function get_hotkey_deprecation_notice(originalHotkey, replacementHotkey)
     );
 }
 
-let shown_deprecation_notices = [];
+let shown_deprecation_notices: string[] = [];
 
-export function maybe_show_deprecation_notice(key) {
+export function maybe_show_deprecation_notice(key: string): void {
     let message;
     const isCmdOrCtrl = common.has_mac_keyboard() ? "Cmd" : "Ctrl";
     switch (key) {
@@ -56,7 +59,9 @@ export function maybe_show_deprecation_notice(key) {
             html_heading: $t_html({defaultMessage: "Deprecation notice"}),
             html_body: message,
             html_submit_button: $t_html({defaultMessage: "Got it"}),
-            on_click() {},
+            on_click() {
+                return;
+            },
             close_on_submit: true,
             focus_submit_on_open: true,
             single_footer_button: true,