diff --git a/lib/shared/updates/update-thread-read-status-spec.js b/lib/shared/updates/update-thread-read-status-spec.js
index cbcc29826..a10f055ee 100644
--- a/lib/shared/updates/update-thread-read-status-spec.js
+++ b/lib/shared/updates/update-thread-read-status-spec.js
@@ -1,101 +1,109 @@
 // @flow
 
 import t from 'tcomb';
 
 import type { UpdateSpec } from './update-spec.js';
-import type {
-  LegacyRawThreadInfo,
-  LegacyRawThreadInfos,
-} from '../../types/thread-types.js';
+import type { RawThreadInfos } from '../../types/thread-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import type {
   ThreadReadStatusUpdateInfo,
   ThreadReadStatusRawUpdateInfo,
   ThreadReadStatusUpdateData,
 } from '../../types/update-types.js';
 import { tID, tNumber, tShape } from '../../utils/validation-utils.js';
 
 export const updateThreadReadStatusSpec: UpdateSpec<
   ThreadReadStatusUpdateInfo,
   ThreadReadStatusRawUpdateInfo,
   ThreadReadStatusUpdateData,
 > = Object.freeze({
   generateOpsForThreadUpdates(
-    storeThreadInfos: LegacyRawThreadInfos,
+    storeThreadInfos: RawThreadInfos,
     update: ThreadReadStatusUpdateInfo,
   ) {
-    const storeThreadInfo: ?LegacyRawThreadInfo =
-      storeThreadInfos[update.threadID];
     if (
-      !storeThreadInfo ||
-      storeThreadInfo.currentUser.unread === update.unread
+      !storeThreadInfos[update.threadID] ||
+      storeThreadInfos[update.threadID].currentUser.unread === update.unread
     ) {
       return null;
     }
-    const updatedThread = {
-      ...storeThreadInfo,
-      currentUser: {
-        ...storeThreadInfo.currentUser,
-        unread: update.unread,
-      },
-    };
+    const storeThreadInfo = storeThreadInfos[update.threadID];
+
+    let updatedThread;
+    if (storeThreadInfo.minimallyEncoded) {
+      updatedThread = {
+        ...storeThreadInfo,
+        currentUser: {
+          ...storeThreadInfo.currentUser,
+          unread: update.unread,
+        },
+      };
+    } else {
+      updatedThread = {
+        ...storeThreadInfo,
+        currentUser: {
+          ...storeThreadInfo.currentUser,
+          unread: update.unread,
+        },
+      };
+    }
     return [
       {
         type: 'replace',
         payload: {
           id: update.threadID,
           threadInfo: updatedThread,
         },
       },
     ];
   },
   rawUpdateInfoFromRow(row: Object) {
     const { threadID, unread } = JSON.parse(row.content);
     return {
       type: updateTypes.UPDATE_THREAD_READ_STATUS,
       id: row.id.toString(),
       time: row.time,
       threadID,
       unread,
     };
   },
   updateContentForServerDB(data: ThreadReadStatusUpdateData) {
     const { threadID, unread } = data;
     return JSON.stringify({ threadID, unread });
   },
   rawInfoFromData(data: ThreadReadStatusUpdateData, id: string) {
     return {
       type: updateTypes.UPDATE_THREAD_READ_STATUS,
       id,
       time: data.time,
       threadID: data.threadID,
       unread: data.unread,
     };
   },
   updateInfoFromRawInfo(info: ThreadReadStatusRawUpdateInfo) {
     return {
       type: updateTypes.UPDATE_THREAD_READ_STATUS,
       id: info.id,
       time: info.time,
       threadID: info.threadID,
       unread: info.unread,
     };
   },
   deleteCondition: new Set([updateTypes.UPDATE_THREAD_READ_STATUS]),
   keyForUpdateData(data: ThreadReadStatusUpdateData) {
     return data.threadID;
   },
   keyForUpdateInfo(info: ThreadReadStatusUpdateInfo) {
     return info.threadID;
   },
   typesOfReplacedUpdatesForMatchingKey: new Set([
     updateTypes.UPDATE_THREAD_READ_STATUS,
   ]),
   infoValidator: tShape<ThreadReadStatusUpdateInfo>({
     type: tNumber(updateTypes.UPDATE_THREAD_READ_STATUS),
     id: t.String,
     time: t.Number,
     threadID: tID,
     unread: t.Boolean,
   }),
 });