diff --git a/lib/permissions/minimally-encoded-raw-thread-info-validators.js b/lib/permissions/minimally-encoded-raw-thread-info-validators.js
--- a/lib/permissions/minimally-encoded-raw-thread-info-validators.js
+++ b/lib/permissions/minimally-encoded-raw-thread-info-validators.js
@@ -8,7 +8,7 @@
 } from './minimally-encoded-thread-permissions.js';
 import { specialRoleValidator } from './special-roles.js';
 import type {
-  MemberInfo,
+  MemberInfoWithPermissions,
   ThreadCurrentUserInfo,
   RawThreadInfo,
   RoleInfo,
@@ -62,17 +62,18 @@
     isDefault: t.maybe(t.Boolean),
   });
 
-const memberInfoValidator: TInterface<MemberInfo> = tShape<MemberInfo>({
-  ...legacyMemberInfoValidator.meta.props,
-  minimallyEncoded: tBool(true),
-  permissions: tHexEncodedPermissionsBitmask,
-});
+const memberInfoWithPermissionsValidator: TInterface<MemberInfoWithPermissions> =
+  tShape<MemberInfoWithPermissions>({
+    ...legacyMemberInfoValidator.meta.props,
+    minimallyEncoded: tBool(true),
+    permissions: tHexEncodedPermissionsBitmask,
+  });
 
 const rawThreadInfoValidator: TInterface<RawThreadInfo> = tShape<RawThreadInfo>(
   {
     ...legacyRawThreadInfoValidator.meta.props,
     minimallyEncoded: tBool(true),
-    members: t.list(memberInfoValidator),
+    members: t.list(memberInfoWithPermissionsValidator),
     roles: t.dict(tID, roleInfoValidator),
     currentUser: threadCurrentUserInfoValidator,
   },
@@ -99,7 +100,7 @@
 ]);
 
 export {
-  memberInfoValidator,
+  memberInfoWithPermissionsValidator,
   roleInfoValidator,
   persistedRoleInfoValidator,
   threadCurrentUserInfoValidator,
diff --git a/lib/permissions/minimally-encoded-thread-permissions.test.js b/lib/permissions/minimally-encoded-thread-permissions.test.js
--- a/lib/permissions/minimally-encoded-thread-permissions.test.js
+++ b/lib/permissions/minimally-encoded-thread-permissions.test.js
@@ -1,7 +1,7 @@
 // @flow
 
 import {
-  memberInfoValidator,
+  memberInfoWithPermissionsValidator,
   persistedRoleInfoValidator,
   rawThreadInfoValidator,
   roleInfoValidator,
@@ -471,7 +471,7 @@
 describe('minimallyEncodedMemberInfoValidator', () => {
   it('should validate correctly formed MinimallyEncodedMemberInfo', () => {
     expect(
-      memberInfoValidator.is({
+      memberInfoWithPermissionsValidator.is({
         minimallyEncoded: true,
         id: 'memberID',
         permissions: 'ABCDEF',
@@ -480,7 +480,7 @@
     ).toBe(true);
 
     expect(
-      memberInfoValidator.is({
+      memberInfoWithPermissionsValidator.is({
         minimallyEncoded: true,
         id: 'memberID',
         permissions: '01b',
@@ -491,7 +491,7 @@
 
   it('should NOT validate malformed MinimallyEncodedMemberInfo', () => {
     expect(
-      memberInfoValidator.is({
+      memberInfoWithPermissionsValidator.is({
         minimallyEncoded: true,
         id: 'memberID',
         permissions: 'INVALID',
@@ -500,7 +500,7 @@
     ).toBe(false);
 
     expect(
-      memberInfoValidator.is({
+      memberInfoWithPermissionsValidator.is({
         minimallyEncoded: true,
         id: 'memberID',
         permissions: 100,
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
@@ -42,7 +42,7 @@
 import type {
   RelativeMemberInfo,
   RawThreadInfo,
-  MemberInfo,
+  MemberInfoWithPermissions,
   RoleInfo,
   ThreadInfo,
 } from '../types/minimally-encoded-thread-permissions-types.js';
@@ -139,7 +139,7 @@
     return _mapValues((threadInfo: ThreadInfo) => {
       const keyedMembers = _keyBy('id')(threadInfo.members);
       const keyedMembersToRole = _mapValues(
-        (member: MemberInfo | RelativeMemberInfo) => {
+        (member: MemberInfoWithPermissions | RelativeMemberInfo) => {
           return member.role ? threadInfo.roles[member.role] : null;
         },
       )(keyedMembers);
@@ -304,7 +304,7 @@
 }
 
 function threadActualMembers(
-  memberInfos: $ReadOnlyArray<MemberInfo | RelativeMemberInfo>,
+  memberInfos: $ReadOnlyArray<MemberInfoWithPermissions | RelativeMemberInfo>,
 ): $ReadOnlyArray<string> {
   return memberInfos
     .filter(memberInfo => memberInfo.role)
@@ -312,7 +312,7 @@
 }
 
 function threadOtherMembers<
-  T: LegacyMemberInfo | MemberInfo | RelativeMemberInfo,
+  T: LegacyMemberInfo | MemberInfoWithPermissions | RelativeMemberInfo,
 >(memberInfos: $ReadOnlyArray<T>, viewerID: ?string): $ReadOnlyArray<T> {
   return memberInfos.filter(
     memberInfo => memberInfo.role && memberInfo.id !== viewerID,
@@ -1002,7 +1002,7 @@
 // Since we don't have access to all of the ancestor ThreadInfos, we approximate
 // "parent admin" as anybody with CHANGE_ROLE permissions.
 function memberHasAdminPowers(
-  memberInfo: LegacyMemberInfo | MemberInfo | ServerMemberInfo,
+  memberInfo: LegacyMemberInfo | MemberInfoWithPermissions | ServerMemberInfo,
 ): boolean {
   if (memberInfo.minimallyEncoded) {
     return hasPermission(memberInfo.permissions, threadPermissions.CHANGE_ROLE);
diff --git a/lib/types/minimally-encoded-thread-permissions-types.js b/lib/types/minimally-encoded-thread-permissions-types.js
--- a/lib/types/minimally-encoded-thread-permissions-types.js
+++ b/lib/types/minimally-encoded-thread-permissions-types.js
@@ -99,7 +99,7 @@
   };
 };
 
-export type MemberInfo = $ReadOnly<{
+export type MemberInfoWithPermissions = $ReadOnly<{
   ...LegacyMemberInfo,
   +minimallyEncoded: true,
   +permissions: string,
@@ -107,7 +107,7 @@
 
 const minimallyEncodeMemberInfo = (
   memberInfo: LegacyMemberInfo,
-): MemberInfo => {
+): MemberInfoWithPermissions => {
   invariant(
     !('minimallyEncoded' in memberInfo),
     'memberInfo is already minimally encoded.',
@@ -120,7 +120,7 @@
 };
 
 const decodeMinimallyEncodedMemberInfo = (
-  minimallyEncodedMemberInfo: MemberInfo,
+  minimallyEncodedMemberInfo: MemberInfoWithPermissions,
 ): LegacyMemberInfo => {
   const { minimallyEncoded, ...rest } = minimallyEncodedMemberInfo;
   return {
@@ -143,7 +143,7 @@
 export type RawThreadInfo = $ReadOnly<{
   ...LegacyRawThreadInfo,
   +minimallyEncoded: true,
-  +members: $ReadOnlyArray<MemberInfo>,
+  +members: $ReadOnlyArray<MemberInfoWithPermissions>,
   +roles: { +[id: string]: RoleInfo },
   +currentUser: ThreadCurrentUserInfo,
 }>;
diff --git a/lib/utils/thread-ops-utils.js b/lib/utils/thread-ops-utils.js
--- a/lib/utils/thread-ops-utils.js
+++ b/lib/utils/thread-ops-utils.js
@@ -3,12 +3,12 @@
 import invariant from 'invariant';
 
 import {
-  memberInfoValidator,
+  memberInfoWithPermissionsValidator,
   persistedRoleInfoValidator,
   threadCurrentUserInfoValidator,
 } from '../permissions/minimally-encoded-raw-thread-info-validators.js';
 import type {
-  MemberInfo,
+  MemberInfoWithPermissions,
   RawThreadInfo,
   RoleInfo,
 } from '../types/minimally-encoded-thread-permissions-types.js';
@@ -46,18 +46,17 @@
 ): RawThreadInfo {
   // 1. Validate and potentially minimally encode `rawMembers`.
   const rawMembers = JSON.parse(clientDBThreadInfo.members);
-  const minimallyEncodedMembers: $ReadOnlyArray<MemberInfo> = rawMembers.map(
-    rawMember => {
+  const minimallyEncodedMembers: $ReadOnlyArray<MemberInfoWithPermissions> =
+    rawMembers.map(rawMember => {
       invariant(
-        memberInfoValidator.is(rawMember) ||
+        memberInfoWithPermissionsValidator.is(rawMember) ||
           legacyMemberInfoValidator.is(rawMember),
         'rawMember must be valid [MinimallyEncoded/Legacy]MemberInfo',
       );
       return rawMember.minimallyEncoded
         ? rawMember
         : minimallyEncodeMemberInfo(rawMember);
-    },
-  );
+    });
 
   // 2. Validate and potentially minimally encode `rawRoles`.
   const rawRoles = JSON.parse(clientDBThreadInfo.roles);