diff --git a/lib/utils/thread-ops-utils.js b/lib/utils/thread-ops-utils.js
index 4b81271f9..970df899b 100644
--- a/lib/utils/thread-ops-utils.js
+++ b/lib/utils/thread-ops-utils.js
@@ -1,79 +1,103 @@
 // @flow
 
-import type { MinimallyEncodedRawThreadInfo } from '../types/minimally-encoded-thread-permissions-types.js';
-import { decodeMinimallyEncodedRawThreadInfo } from '../types/minimally-encoded-thread-permissions-types.js';
+import invariant from 'invariant';
+
+import { minimallyEncodedMemberInfoValidator } from '../permissions/minimally-encoded-thread-permissions-validators.js';
+import type {
+  MinimallyEncodedMemberInfo,
+  MinimallyEncodedRawThreadInfo,
+} from '../types/minimally-encoded-thread-permissions-types.js';
+import {
+  decodeMinimallyEncodedRawThreadInfo,
+  minimallyEncodeMemberInfo,
+} from '../types/minimally-encoded-thread-permissions-types.js';
 import { assertThreadType } from '../types/thread-types-enum.js';
 import {
   type ClientDBThreadInfo,
+  legacyMemberInfoValidator,
   type LegacyRawThreadInfo,
   type RawThreadInfo,
 } from '../types/thread-types.js';
 
 function convertRawThreadInfoToClientDBThreadInfo(
   rawThreadInfo: RawThreadInfo,
 ): ClientDBThreadInfo {
   const { minimallyEncoded, ...rest } = rawThreadInfo;
   return {
     ...rest,
     creationTime: rawThreadInfo.creationTime.toString(),
     members: JSON.stringify(rawThreadInfo.members),
     roles: JSON.stringify(rawThreadInfo.roles),
     currentUser: JSON.stringify(rawThreadInfo.currentUser),
     avatar: rawThreadInfo.avatar ? JSON.stringify(rawThreadInfo.avatar) : null,
   };
 }
 
 function convertClientDBThreadInfoToRawThreadInfo(
   clientDBThreadInfo: ClientDBThreadInfo,
 ): MinimallyEncodedRawThreadInfo {
+  // 1. Validate and potentially minimally encode `rawMembers`.
+  const rawMembers = JSON.parse(clientDBThreadInfo.members);
+  const minimallyEncodedMembers: $ReadOnlyArray<MinimallyEncodedMemberInfo> =
+    rawMembers.map(rawMember => {
+      invariant(
+        minimallyEncodedMemberInfoValidator.is(rawMember) ||
+          legacyMemberInfoValidator.is(rawMember),
+        'rawMember must be valid [MinimallyEncoded/Legacy]MemberInfo',
+      );
+      return rawMember.minimallyEncoded
+        ? rawMember
+        : minimallyEncodeMemberInfo(rawMember);
+    });
+
   let rawThreadInfo: MinimallyEncodedRawThreadInfo = {
     minimallyEncoded: true,
     id: clientDBThreadInfo.id,
     type: assertThreadType(clientDBThreadInfo.type),
     name: clientDBThreadInfo.name,
     description: clientDBThreadInfo.description,
     color: clientDBThreadInfo.color,
     creationTime: Number(clientDBThreadInfo.creationTime),
     parentThreadID: clientDBThreadInfo.parentThreadID,
     containingThreadID: clientDBThreadInfo.containingThreadID,
     community: clientDBThreadInfo.community,
-    members: JSON.parse(clientDBThreadInfo.members),
+    members: minimallyEncodedMembers,
     roles: JSON.parse(clientDBThreadInfo.roles),
     currentUser: JSON.parse(clientDBThreadInfo.currentUser),
     repliesCount: clientDBThreadInfo.repliesCount,
     pinnedCount: clientDBThreadInfo.pinnedCount,
   };
 
   if (clientDBThreadInfo.sourceMessageID) {
     rawThreadInfo = {
       ...rawThreadInfo,
       sourceMessageID: clientDBThreadInfo.sourceMessageID,
     };
   }
 
   if (clientDBThreadInfo.avatar) {
     rawThreadInfo = {
       ...rawThreadInfo,
       avatar: JSON.parse(clientDBThreadInfo.avatar),
     };
   }
 
   return rawThreadInfo;
 }
 
 // WARNING: Do not consume or delete this function!
 // This function is being left in the codebase **SOLELY** to ensure that
 // previous `native` redux migrations continue to behave as expected.
 function deprecatedConvertClientDBThreadInfoToRawThreadInfo(
   clientDBThreadInfo: ClientDBThreadInfo,
 ): LegacyRawThreadInfo {
   const minimallyEncoded =
     convertClientDBThreadInfoToRawThreadInfo(clientDBThreadInfo);
   return decodeMinimallyEncodedRawThreadInfo(minimallyEncoded);
 }
 
 export {
   convertRawThreadInfoToClientDBThreadInfo,
   convertClientDBThreadInfoToRawThreadInfo,
   deprecatedConvertClientDBThreadInfoToRawThreadInfo,
 };