diff --git a/lib/types/account-types.js b/lib/types/account-types.js
--- a/lib/types/account-types.js
+++ b/lib/types/account-types.js
@@ -68,19 +68,19 @@
 };
 
 export type RegisterResponse = {
-  id: string,
-  rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
-  currentUserInfo: LoggedInUserInfo,
-  cookieChange: {
-    threadInfos: RawThreadInfos,
-    userInfos: $ReadOnlyArray<UserInfo>,
+  +id: string,
+  +rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
+  +currentUserInfo: LoggedInUserInfo,
+  +cookieChange: {
+    +threadInfos: RawThreadInfos,
+    +userInfos: $ReadOnlyArray<UserInfo>,
   },
 };
 
 export type RegisterResult = {
   +currentUserInfo: LoggedInUserInfo,
   +rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
-  +threadInfos: RawThreadInfos,
+  +threadInfos: MinimallyEncodedRawThreadInfos,
   +userInfos: $ReadOnlyArray<UserInfo>,
   +calendarQuery: CalendarQuery,
 };