diff --git a/tools/test-js-with-node b/tools/test-js-with-node
index b7ca09780d..41b640472e 100755
--- a/tools/test-js-with-node
+++ b/tools/test-js-with-node
@@ -211,7 +211,7 @@ EXEMPT_FILES = make_set(
         "web/src/settings_panel_menu.js",
         "web/src/settings_playgrounds.js",
         "web/src/settings_profile_fields.js",
-        "web/src/settings_realm_domains.js",
+        "web/src/settings_realm_domains.ts",
         "web/src/settings_realm_user_settings_defaults.js",
         "web/src/settings_sections.js",
         "web/src/settings_streams.js",
diff --git a/web/src/page_params.ts b/web/src/page_params.ts
index 82a1637ac8..87cdebd347 100644
--- a/web/src/page_params.ts
+++ b/web/src/page_params.ts
@@ -63,6 +63,7 @@ export const page_params: {
     realm_create_web_public_stream_policy: number;
     realm_delete_own_message_policy: number;
     realm_description: string;
+    realm_domains: {domain: string; allow_subdomains: boolean}[];
     realm_edit_topic_policy: number;
     realm_email_changes_disabled: boolean;
     realm_enable_guest_user_indicator: boolean;
diff --git a/web/src/settings_realm_domains.js b/web/src/settings_realm_domains.ts
similarity index 92%
rename from web/src/settings_realm_domains.js
rename to web/src/settings_realm_domains.ts
index c2e656fa53..70936bae7b 100644
--- a/web/src/settings_realm_domains.js
+++ b/web/src/settings_realm_domains.ts
@@ -9,7 +9,12 @@ import {$t_html} from "./i18n";
 import {page_params} from "./page_params";
 import * as ui_report from "./ui_report";
 
-export function populate_realm_domains_table(realm_domains) {
+type RealmDomain = {
+    domain: string;
+    allow_subdomains: boolean;
+};
+
+export function populate_realm_domains_table(realm_domains: RealmDomain[]): void {
     // Don't populate the table if the realm domains modal isn't open.
     if ($("#realm_domains_modal").length === 0) {
         return;
@@ -27,19 +32,19 @@ export function populate_realm_domains_table(realm_domains) {
     }
 }
 
-function fade_status_element($elem) {
+function fade_status_element($elem: JQuery): void {
     setTimeout(() => {
         $elem.fadeOut(500);
     }, 3000);
 }
 
-export function setup_realm_domains_modal_handlers() {
+export function setup_realm_domains_modal_handlers(): void {
     $("#realm_domains_table").on("click", ".delete_realm_domain", function () {
         const domain = $(this).parents("tr").find(".domain").text();
         const url = "/json/realm/domains/" + domain;
         const $realm_domains_info = $(".realm_domains_info");
 
-        channel.del({
+        void channel.del({
             url,
             success() {
                 ui_report.success(
@@ -65,7 +70,7 @@ export function setup_realm_domains_modal_handlers() {
             allow_subdomains: JSON.stringify(allow_subdomains),
         };
 
-        channel.patch({
+        void channel.patch({
             url,
             data,
             success() {
@@ -111,7 +116,7 @@ export function setup_realm_domains_modal_handlers() {
             allow_subdomains: JSON.stringify(allow_subdomains),
         };
 
-        channel.post({
+        void channel.post({
             url: "/json/realm/domains",
             data,
             success() {
@@ -134,7 +139,7 @@ export function setup_realm_domains_modal_handlers() {
     });
 }
 
-export function show_realm_domains_modal() {
+export function show_realm_domains_modal(): void {
     const realm_domains_table_body = render_realm_domains_modal();
 
     dialog_widget.launch({