diff --git a/lib/types/request-types.js b/lib/types/request-types.js
--- a/lib/types/request-types.js
+++ b/lib/types/request-types.js
@@ -316,7 +316,8 @@
   | ClientThreadInconsistencyClientResponse
   | ClientEntryInconsistencyClientResponse;
 
-export const processServerRequestsActionType = 'PROCESS_SERVER_REQUESTS';
+export const processServerRequestsActionType =
+  'PROCESS_SERVER_REQUESTS' as const;
 export type ProcessServerRequestsPayload = {
   +serverRequests: $ReadOnlyArray<ClientServerRequest>,
   +calendarQuery: CalendarQuery,
diff --git a/lib/types/thread-activity-types.js b/lib/types/thread-activity-types.js
--- a/lib/types/thread-activity-types.js
+++ b/lib/types/thread-activity-types.js
@@ -1,7 +1,7 @@
 // @flow
 
 export const updateThreadLastNavigatedActionType =
-  'UPDATE_THREAD_LAST_NAVIGATED';
+  'UPDATE_THREAD_LAST_NAVIGATED' as const;
 
 export type ThreadActivityStoreEntry =
   | {
diff --git a/native/navigation/action-types.js b/native/navigation/action-types.js
--- a/native/navigation/action-types.js
+++ b/native/navigation/action-types.js
@@ -1,20 +1,20 @@
 // @flow
 
 // RootRouter
-export const logInActionType = 'LOG_IN';
-export const logOutActionType = 'LOG_OUT';
-export const clearRootModalsActionType = 'CLEAR_ROOT_MODALS';
-export const setNavStateActionType = 'SET_NAV_STATE';
+export const logInActionType = 'LOG_IN' as const;
+export const logOutActionType = 'LOG_OUT' as const;
+export const clearRootModalsActionType = 'CLEAR_ROOT_MODALS' as const;
+export const setNavStateActionType = 'SET_NAV_STATE' as const;
 
 // OverlayRouter
-export const clearOverlayModalsActionType = 'CLEAR_OVERLAY_MODALS';
-export const setRouteParamsActionType = 'SET_ROUTE_PARAMS';
+export const clearOverlayModalsActionType = 'CLEAR_OVERLAY_MODALS' as const;
+export const setRouteParamsActionType = 'SET_ROUTE_PARAMS' as const;
 
 // ChatRouter
-export const clearScreensActionType = 'CLEAR_SCREENS';
-export const replaceWithThreadActionType = 'REPLACE_WITH_THREAD';
-export const clearThreadsActionType = 'CLEAR_THREADS';
-export const pushNewThreadActionType = 'PUSH_NEW_THREAD';
+export const clearScreensActionType = 'CLEAR_SCREENS' as const;
+export const replaceWithThreadActionType = 'REPLACE_WITH_THREAD' as const;
+export const clearThreadsActionType = 'CLEAR_THREADS' as const;
+export const pushNewThreadActionType = 'PUSH_NEW_THREAD' as const;
 
 // RegistrationRouter
-export const reconnectEthereumActionType = 'RECONNECT_ETHEREUM';
+export const reconnectEthereumActionType = 'RECONNECT_ETHEREUM' as const;