diff --git a/lib/shared/transforms/message-store-transform.js b/lib/shared/transforms/message-store-transform.js
new file mode 100644
--- /dev/null
+++ b/lib/shared/transforms/message-store-transform.js
@@ -0,0 +1,63 @@
+// @flow
+
+import { createTransform } from 'redux-persist';
+import type { Transform } from 'redux-persist/es/types.js';
+
+import type {
+  LocalMessageInfo,
+  MessageStore,
+} from '../../types/message-types.js';
+
+// On native, after migration 31, we'll no longer want to persist
+// `messageStore.messages` and `messageStore.threads` via redux-persist.
+// On web we want to start persisting `messageStore.messages` and
+// `messageStore.threads in the database.
+
+// However, we DO want to continue (or start on web) persisting everything in
+// `messageStore` EXCEPT for `messages` and `threads`. The `blacklist` property
+// in `persistConfig` allows us to specify top-level keys that shouldn't be
+// persisted. However, we aren't able to specify nested keys in `blacklist`.
+// As a result, if we want to prevent nested keys from being persisted we'll
+// need to use `createTransform(...)` to specify an `inbound` function that
+// allows us to modify the `state` object before it's passed through
+// `JSON.stringify(...)` and written to disk. We specify the keys for which
+// this transformation should be executed in the `whitelist` property of the
+// `config` object that's passed to `createTransform(...)`.
+type PersistedMessageStore = {
+  +local: { +[id: string]: LocalMessageInfo },
+  +currentAsOf: { +[keyserverID: string]: number },
+};
+const messageStoreMessagesBlocklistTransform: Transform = createTransform(
+  (state: MessageStore): PersistedMessageStore => {
+    const { messages, threads, ...messageStoreSansMessages } = state;
+    return { ...messageStoreSansMessages };
+  },
+  (state: MessageStore): MessageStore => {
+    // On web `state.threads` and `state.messages` should always be undefined.
+    // On native the situation is more complicated:
+    // We typically expect `messageStore.messages` to be `undefined` because
+    // messages are persisted in the SQLite `messages` table rather than via
+    // `redux-persist`. In this case we want to set `messageStore.messages`
+    // to {} so we don't run into issues with `messageStore.messages` being
+    // `undefined` (https://phab.comm.dev/D5545).
+    //
+    // However, in the case that a user is upgrading from a client where
+    // `persistConfig.version` < 31, we expect `messageStore.messages` to
+    // contain messages stored via `redux-persist` that we need in order
+    // to correctly populate the SQLite `messages` table in migration 31
+    // (https://phab.comm.dev/D2600).
+    //
+    // However, because `messageStoreMessagesBlocklistTransform` modifies
+    // `messageStore` before migrations are run, we need to make sure we aren't
+    // inadvertently clearing `messageStore.messages` (by setting to {}) before
+    // messages are stored in SQLite (https://linear.app/comm/issue/ENG-2377).
+    return {
+      ...state,
+      threads: state.threads ?? {},
+      messages: state.messages ?? {},
+    };
+  },
+  { whitelist: ['messageStore'] },
+);
+
+export { messageStoreMessagesBlocklistTransform };
diff --git a/native/redux/persist.js b/native/redux/persist.js
--- a/native/redux/persist.js
+++ b/native/redux/persist.js
@@ -54,6 +54,7 @@
   assertAllThreadInfosAreLegacy,
 } from 'lib/shared/thread-utils.js';
 import { keyserverStoreTransform } from 'lib/shared/transforms/keyserver-store-transform.js';
+import { messageStoreMessagesBlocklistTransform } from 'lib/shared/transforms/message-store-transform.js';
 import {
   DEPRECATED_unshimMessageStore,
   unshimFunc,
@@ -67,8 +68,6 @@
   type MessageType,
 } from 'lib/types/message-types-enum.js';
 import {
-  type LocalMessageInfo,
-  type MessageStore,
   type MessageStoreThreads,
   type RawMessageInfo,
 } from 'lib/types/message-types.js';
@@ -1206,52 +1205,6 @@
   },
 };
 
-// After migration 31, we'll no longer want to persist `messageStore.messages`
-// via redux-persist. However, we DO want to continue persisting everything in
-// `messageStore` EXCEPT for `messages`. The `blacklist` property in
-// `persistConfig` allows us to specify top-level keys that shouldn't be
-// persisted. However, we aren't able to specify nested keys in `blacklist`.
-// As a result, if we want to prevent nested keys from being persisted we'll
-// need to use `createTransform(...)` to specify an `inbound` function that
-// allows us to modify the `state` object before it's passed through
-// `JSON.stringify(...)` and written to disk. We specify the keys for which
-// this transformation should be executed in the `whitelist` property of the
-// `config` object that's passed to `createTransform(...)`.
-type PersistedMessageStore = {
-  +local: { +[id: string]: LocalMessageInfo },
-  +currentAsOf: { +[keyserverID: string]: number },
-};
-const messageStoreMessagesBlocklistTransform: Transform = createTransform(
-  (state: MessageStore): PersistedMessageStore => {
-    const { messages, threads, ...messageStoreSansMessages } = state;
-    return { ...messageStoreSansMessages };
-  },
-  (state: MessageStore): MessageStore => {
-    // We typically expect `messageStore.messages` to be `undefined` because
-    // messages are persisted in the SQLite `messages` table rather than via
-    // `redux-persist`. In this case we want to set `messageStore.messages`
-    // to {} so we don't run into issues with `messageStore.messages` being
-    // `undefined` (https://phab.comm.dev/D5545).
-    //
-    // However, in the case that a user is upgrading from a client where
-    // `persistConfig.version` < 31, we expect `messageStore.messages` to
-    // contain messages stored via `redux-persist` that we need in order
-    // to correctly populate the SQLite `messages` table in migration 31
-    // (https://phab.comm.dev/D2600).
-    //
-    // However, because `messageStoreMessagesBlocklistTransform` modifies
-    // `messageStore` before migrations are run, we need to make sure we aren't
-    // inadvertently clearing `messageStore.messages` (by setting to {}) before
-    // messages are stored in SQLite (https://linear.app/comm/issue/ENG-2377).
-    return {
-      ...state,
-      threads: state.threads ?? {},
-      messages: state.messages ?? {},
-    };
-  },
-  { whitelist: ['messageStore'] },
-);
-
 type PersistedReportStore = $Diff<
   ReportStore,
   { +queuedReports: $ReadOnlyArray<ClientReportCreationRequest> },