diff --git a/lib/shared/messages/join-thread-message-spec.js b/lib/shared/messages/join-thread-message-spec.js
--- a/lib/shared/messages/join-thread-message-spec.js
+++ b/lib/shared/messages/join-thread-message-spec.js
@@ -15,11 +15,13 @@
 import type { NotifTexts } from '../../types/notif-types';
 import type { ThreadInfo } from '../../types/thread-types';
 import type { RelativeUserInfo } from '../../types/user-types';
-import { ET, type EntityText } from '../../utils/entity-text';
+import {
+  ET,
+  type EntityText,
+  pluralizeEntityText,
+} from '../../utils/entity-text';
 import { values } from '../../utils/objects';
-import { pluralize } from '../../utils/text-utils';
-import { stringForUser } from '../user-utils';
-import type { MessageSpec, NotificationTextsParams } from './message-spec';
+import type { MessageSpec } from './message-spec';
 import { joinResult } from './utils';
 
 export const joinThreadMessageSpec: MessageSpec<
@@ -82,7 +84,6 @@
   async notificationTexts(
     messageInfos: $ReadOnlyArray<MessageInfo>,
     threadInfo: ThreadInfo,
-    params: NotificationTextsParams,
   ): Promise<NotifTexts> {
     const joinerArray = {};
     for (const messageInfo of messageInfos) {
@@ -93,10 +94,14 @@
       joinerArray[messageInfo.creator.id] = messageInfo.creator;
     }
     const joiners = values(joinerArray);
-    const joinersString = pluralize(joiners.map(stringForUser));
+    const joiningUsers = pluralizeEntityText(
+      joiners.map(user => ET`${ET.user({ userInfo: user })}`),
+    );
+
+    const body = ET`${joiningUsers} joined`;
+    const thread = ET.thread({ display: 'shortName', threadInfo });
+    const merged = ET`${body} ${thread}`;
 
-    const body = `${joinersString} joined`;
-    const merged = `${body} ${params.notifThreadName(threadInfo)}`;
     return {
       merged,
       title: threadInfo.uiName,
diff --git a/lib/shared/messages/leave-thread-message-spec.js b/lib/shared/messages/leave-thread-message-spec.js
--- a/lib/shared/messages/leave-thread-message-spec.js
+++ b/lib/shared/messages/leave-thread-message-spec.js
@@ -15,11 +15,13 @@
 import type { NotifTexts } from '../../types/notif-types';
 import type { ThreadInfo } from '../../types/thread-types';
 import type { RelativeUserInfo } from '../../types/user-types';
-import { ET, type EntityText } from '../../utils/entity-text';
+import {
+  ET,
+  type EntityText,
+  pluralizeEntityText,
+} from '../../utils/entity-text';
 import { values } from '../../utils/objects';
-import { pluralize } from '../../utils/text-utils';
-import { stringForUser } from '../user-utils';
-import type { MessageSpec, NotificationTextsParams } from './message-spec';
+import type { MessageSpec } from './message-spec';
 import { joinResult } from './utils';
 
 export const leaveThreadMessageSpec: MessageSpec<
@@ -82,7 +84,6 @@
   async notificationTexts(
     messageInfos: $ReadOnlyArray<MessageInfo>,
     threadInfo: ThreadInfo,
-    params: NotificationTextsParams,
   ): Promise<NotifTexts> {
     const leaverBeavers = {};
     for (const messageInfo of messageInfos) {
@@ -93,10 +94,14 @@
       leaverBeavers[messageInfo.creator.id] = messageInfo.creator;
     }
     const leavers = values(leaverBeavers);
-    const leaversString = pluralize(leavers.map(stringForUser));
+    const leavingUsers = pluralizeEntityText(
+      leavers.map(user => ET`${ET.user({ userInfo: user })}`),
+    );
+
+    const body = ET`${leavingUsers} left`;
+    const thread = ET.thread({ display: 'shortName', threadInfo });
+    const merged = ET`${body} ${thread}`;
 
-    const body = `${leaversString} left`;
-    const merged = `${body} ${params.notifThreadName(threadInfo)}`;
     return {
       merged,
       title: threadInfo.uiName,