diff --git a/keyserver/src/shared/state-sync/threads-state-sync-spec.js b/keyserver/src/shared/state-sync/threads-state-sync-spec.js
--- a/keyserver/src/shared/state-sync/threads-state-sync-spec.js
+++ b/keyserver/src/shared/state-sync/threads-state-sync-spec.js
@@ -1,11 +1,13 @@
 // @flow
 
+import { rawThreadInfoValidator } from 'lib/permissions/minimally-encoded-thread-permissions-validators.js';
 import { threadsStateSyncSpec as libSpec } from 'lib/shared/state-sync/threads-state-sync-spec.js';
 import type { ClientThreadInconsistencyReportCreationRequest } from 'lib/types/report-types.js';
 import {
   type LegacyRawThreadInfos,
   type LegacyRawThreadInfo,
-  legacyRawThreadInfoValidator,
+  type RawThreadInfo,
+  type RawThreadInfos,
 } from 'lib/types/thread-types.js';
 import { hash, combineUnorderedHashes, values } from 'lib/utils/objects.js';
 
@@ -40,10 +42,10 @@
   return result.threadInfos;
 }
 
-function getServerInfosHash(infos: LegacyRawThreadInfos) {
+function getServerInfosHash(infos: RawThreadInfos) {
   return combineUnorderedHashes(values(infos).map(getServerInfoHash));
 }
 
-function getServerInfoHash(info: LegacyRawThreadInfo) {
-  return hash(validateOutput(null, legacyRawThreadInfoValidator, info));
+function getServerInfoHash(info: RawThreadInfo) {
+  return hash(validateOutput(null, rawThreadInfoValidator, info));
 }
diff --git a/lib/permissions/minimally-encoded-thread-permissions-validators.js b/lib/permissions/minimally-encoded-thread-permissions-validators.js
--- a/lib/permissions/minimally-encoded-thread-permissions-validators.js
+++ b/lib/permissions/minimally-encoded-thread-permissions-validators.js
@@ -1,5 +1,5 @@
 // @flow
-import t, { type TInterface } from 'tcomb';
+import t, { type TInterface, TUnion } from 'tcomb';
 
 import {
   tHexEncodedPermissionsBitmask,
@@ -21,6 +21,7 @@
   threadCurrentUserInfoValidator,
   legacyThreadInfoValidator,
 } from '../types/thread-types.js';
+import type { RawThreadInfo } from '../types/thread-types.js';
 import { tBool, tID, tShape } from '../utils/validation-utils.js';
 
 const minimallyEncodedRoleInfoValidator: TInterface<MinimallyEncodedRoleInfo> =
@@ -75,6 +76,11 @@
     currentUser: minimallyEncodedThreadCurrentUserInfoValidator,
   });
 
+export const rawThreadInfoValidator: TUnion<RawThreadInfo> = t.union([
+  legacyRawThreadInfoValidator,
+  minimallyEncodedRawThreadInfoValidator,
+]);
+
 export {
   minimallyEncodedRoleInfoValidator,
   minimallyEncodedThreadCurrentUserInfoValidator,
diff --git a/lib/types/thread-types.js b/lib/types/thread-types.js
--- a/lib/types/thread-types.js
+++ b/lib/types/thread-types.js
@@ -145,6 +145,9 @@
   });
 
 export type RawThreadInfo = LegacyRawThreadInfo | MinimallyEncodedRawThreadInfo;
+export type RawThreadInfos = {
+  +[id: string]: RawThreadInfo,
+};
 
 export type LegacyThreadInfo = {
   +id: string,