diff --git a/lib/shared/updates/update-thread-read-status-spec.js b/lib/shared/updates/update-thread-read-status-spec.js
--- a/lib/shared/updates/update-thread-read-status-spec.js
+++ b/lib/shared/updates/update-thread-read-status-spec.js
@@ -4,8 +4,8 @@
 
 import type { UpdateSpec } from './update-spec.js';
 import type {
-  LegacyRawThreadInfo,
-  LegacyRawThreadInfos,
+  RawThreadInfo,
+  RawThreadInfos,
 } from '../../types/thread-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import type {
@@ -21,33 +21,57 @@
   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,
+    const storeThreadInfo: RawThreadInfo = storeThreadInfos[update.threadID];
+    // TODO (atul): Try to get rid of this ridiculous branching.
+    if (storeThreadInfo.minimallyEncoded) {
+      const currentUser = storeThreadInfo.currentUser;
+      const updatedUser = {
+        role: currentUser.role,
+        subscription: currentUser.subscription,
         unread: update.unread,
-      },
-    };
-    return [
-      {
-        type: 'replace',
-        payload: {
-          id: update.threadID,
-          threadInfo: updatedThread,
+        minimallyEncoded: true,
+        permissions: currentUser.permissions,
+      };
+      const updatedThread = {
+        ...storeThreadInfo,
+        currentUser: updatedUser,
+      };
+      return [
+        {
+          type: 'replace',
+          payload: {
+            id: update.threadID,
+            threadInfo: updatedThread,
+          },
+        },
+      ];
+    } else {
+      const 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);