diff --git a/lib/types/entry-types.js b/lib/types/entry-types.js
--- a/lib/types/entry-types.js
+++ b/lib/types/entry-types.js
@@ -247,3 +247,9 @@
   +calendarQuery: CalendarQuery,
   +calendarQueryAlreadyUpdated: boolean,
 };
+
+export type FetchRevisionsForEntryPayload = {
+  +entryID: string,
+  +text: string,
+  +deleted: boolean,
+};
diff --git a/lib/types/redux-types.js b/lib/types/redux-types.js
--- a/lib/types/redux-types.js
+++ b/lib/types/redux-types.js
@@ -35,6 +35,7 @@
   CalendarQueryUpdateResult,
   CalendarQueryUpdateStartingPayload,
   CalendarQuery,
+  FetchRevisionsForEntryPayload,
 } from './entry-types.js';
 import type {
   CalendarFilter,
@@ -431,11 +432,7 @@
     }
   | {
       +type: 'FETCH_REVISIONS_FOR_ENTRY_SUCCESS',
-      +payload: {
-        +entryID: string,
-        +text: string,
-        +deleted: boolean,
-      },
+      +payload: FetchRevisionsForEntryPayload,
       +loadingInfo: LoadingInfo,
     }
   | {
diff --git a/web/modals/history/history-modal.react.js b/web/modals/history/history-modal.react.js
--- a/web/modals/history/history-modal.react.js
+++ b/web/modals/history/history-modal.react.js
@@ -22,6 +22,7 @@
   EntryInfo,
   CalendarQuery,
   FetchEntryInfosResult,
+  FetchRevisionsForEntryPayload,
 } from 'lib/types/entry-types.js';
 import { type CalendarFilter } from 'lib/types/filter-types.js';
 import type {
@@ -211,7 +212,9 @@
     );
   }
 
-  async fetchRevisionsForEntryAction(entryID: string) {
+  async fetchRevisionsForEntryAction(
+    entryID: string,
+  ): Promise<FetchRevisionsForEntryPayload> {
     const result = await this.props.fetchRevisionsForEntry({ entryID });
     this.setState(prevState => {
       // This merge here will preserve time ordering correctly