diff --git a/lib/selectors/user-selectors.js b/lib/selectors/user-selectors.js
--- a/lib/selectors/user-selectors.js
+++ b/lib/selectors/user-selectors.js
@@ -11,6 +11,10 @@
 import SentencePrefixSearchIndex from '../shared/sentence-prefix-search-index.js';
 import { getSingleOtherUser } from '../shared/thread-utils.js';
 import type { ClientEmojiAvatar } from '../types/avatar-types';
+import type {
+  MinimallyEncodedRawThreadInfo,
+  MinimallyEncodedRelativeMemberInfo,
+} from '../types/minimally-encoded-thread-permissions-types.js';
 import type { BaseAppState } from '../types/redux-types.js';
 import { userRelationshipStatus } from '../types/relationship-types.js';
 import { threadTypes } from '../types/thread-types-enum.js';
@@ -54,7 +58,41 @@
   return relativeUserInfos;
 }
 
-function getRelativeMemberInfos(
+function getMinimallyEncodedRelativeMemberInfos(
+  threadInfo: ?MinimallyEncodedRawThreadInfo,
+  currentUserID: ?string,
+  userInfos: UserInfos,
+): $ReadOnlyArray<MinimallyEncodedRelativeMemberInfo> {
+  const relativeMemberInfos = [];
+  if (!threadInfo) {
+    return relativeMemberInfos;
+  }
+  const memberInfos = threadInfo.members;
+  for (const memberInfo of memberInfos) {
+    if (!memberInfo.role) {
+      continue;
+    }
+    const username = userInfos[memberInfo.id]
+      ? userInfos[memberInfo.id].username
+      : null;
+    if (memberInfo.id === currentUserID) {
+      relativeMemberInfos.unshift({
+        ...memberInfo,
+        username,
+        isViewer: true,
+      });
+    } else {
+      relativeMemberInfos.push({
+        ...memberInfo,
+        username,
+        isViewer: false,
+      });
+    }
+  }
+  return relativeMemberInfos;
+}
+
+function getLegacyRelativeMemberInfos(
   threadInfo: ?LegacyRawThreadInfo,
   currentUserID: ?string,
   userInfos: UserInfos,
@@ -104,7 +142,7 @@
     (state: BaseAppState<>) =>
       state.currentUserInfo && state.currentUserInfo.id,
     (state: BaseAppState<>) => state.userStore.userInfos,
-    getRelativeMemberInfos,
+    getLegacyRelativeMemberInfos,
   );
 };
 
@@ -241,7 +279,8 @@
 
 export {
   userIDsToRelativeUserInfos,
-  getRelativeMemberInfos,
+  getMinimallyEncodedRelativeMemberInfos,
+  getLegacyRelativeMemberInfos,
   relativeMemberInfoSelectorForMembersOfThread,
   userInfoSelectorForPotentialMembers,
   userSearchIndexForPotentialMembers,
diff --git a/lib/shared/thread-utils.js b/lib/shared/thread-utils.js
--- a/lib/shared/thread-utils.js
+++ b/lib/shared/thread-utils.js
@@ -47,7 +47,7 @@
   threadInfosSelectorForThreadType,
 } from '../selectors/thread-selectors.js';
 import {
-  getRelativeMemberInfos,
+  getLegacyRelativeMemberInfos,
   usersWithPersonalThreadSelector,
 } from '../selectors/user-selectors.js';
 import { getUserAvatarForThread } from '../shared/avatar-utils.js';
@@ -904,7 +904,7 @@
     parentThreadID: rawThreadInfo.parentThreadID,
     containingThreadID: rawThreadInfo.containingThreadID,
     community: rawThreadInfo.community,
-    members: getRelativeMemberInfos(rawThreadInfo, viewerID, userInfos),
+    members: getLegacyRelativeMemberInfos(rawThreadInfo, viewerID, userInfos),
     roles: rawThreadInfo.roles,
     currentUser: getCurrentUser(rawThreadInfo, viewerID, userInfos),
     repliesCount: rawThreadInfo.repliesCount,