diff --git a/web/redux/persist.js b/web/redux/persist.js
--- a/web/redux/persist.js
+++ b/web/redux/persist.js
@@ -35,6 +35,7 @@
 import { getConfig } from 'lib/utils/config.js';
 import { parseCookies } from 'lib/utils/cookie-utils.js';
 import { isDev } from 'lib/utils/dev-utils.js';
+import { stripMemberPermissionsFromRawThreadInfos } from 'lib/utils/member-info-utils.js';
 import {
   generateIDSchemaMigrationOpsForDrafts,
   convertDraftStoreToNewIDSchema,
@@ -641,6 +642,45 @@
     },
     ops: [],
   }),
+  [84]: async (state: AppState) => {
+    const sharedWorker = await getCommSharedWorker();
+    const isDatabaseSupported = await sharedWorker.isSupported();
+
+    if (!isDatabaseSupported) {
+      return {
+        state,
+        ops: [],
+      };
+    }
+
+    const stores = await sharedWorker.schedule({
+      type: workerRequestMessageTypes.GET_CLIENT_STORE,
+    });
+
+    const clientDBThreadInfos: ?$ReadOnlyArray<ClientDBThreadInfo> =
+      stores?.store?.threads;
+
+    if (
+      clientDBThreadInfos === null ||
+      clientDBThreadInfos === undefined ||
+      clientDBThreadInfos.length === 0
+    ) {
+      return {
+        state,
+        ops: [],
+      };
+    }
+
+    const dbOperations = createUpdateDBOpsForThreadStoreThreadInfos(
+      clientDBThreadInfos,
+      // We know that we're dealing with `ThinRawThreadInfoWithPermissions`
+      // at the time of this migration.
+      // $FlowFixMe
+      stripMemberPermissionsFromRawThreadInfos,
+    );
+
+    return { state, ops: dbOperations };
+  },
 };
 
 const persistConfig: PersistConfig = {