diff --git a/frontend/src/components/PostEditForm.tsx b/frontend/src/components/PostEditForm.tsx
index 3ac2077..24d2dcc 100644
--- a/frontend/src/components/PostEditForm.tsx
+++ b/frontend/src/components/PostEditForm.tsx
@@ -5,7 +5,7 @@ import PostOriginalCreatedTimeField from '@/components/PostOriginalCreatedTimeFi
 import Label from '@/components/common/Label'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
-import { apiPut } from '@/lib/api'
+import { updatePost } from '@/lib/posts'
 
 import type { FC } from 'react'
 
@@ -44,19 +44,17 @@ export default (({ post, onSave }: Props) => {
   const handleSubmit = async () => {
     try
     {
-      const data = await apiPut<Post> (
-	  `/posts/${ post.id }`,
-	  { title, tags, parent_post_ids: parentPostIds,
-	    original_created_from: originalCreatedFrom,
-	    original_created_before: originalCreatedBefore },
-	  { headers: { 'Content-Type': 'multipart/form-data' } })
+      const data =
+	  await updatePost ({ id: post.id, versionNo: post.versionNo + 1,
+			      title, tags, parentPostIds,
+			      originalCreatedFrom, originalCreatedBefore })
       onSave ({ ...post,
 		title:                  data.title,
 		tags:                   data.tags,
 		parentPosts:            data.parentPosts,
 		childPosts:             data.childPosts,
 		siblingPosts:           data.siblingPosts,
-		originalCreatedFrom:    data.originalCreatedFrom,
+	        originalCreatedFrom:    data.originalCreatedFrom,
 		originalCreatedBefore:  data.originalCreatedBefore } as Post)
       toast ({ description: '更新しました．' })
     }
diff --git a/frontend/src/lib/posts.ts b/frontend/src/lib/posts.ts
index 57907dc..4197148 100644
--- a/frontend/src/lib/posts.ts
+++ b/frontend/src/lib/posts.ts
@@ -1,4 +1,4 @@
-import { apiDelete, apiGet, apiPost } from '@/lib/api'
+import { apiDelete, apiGet, apiPost, apiPut } from '@/lib/api'
 
 import type { FetchPostsParams, Post, PostVersion } from '@/types'
 
@@ -42,6 +42,25 @@ export const fetchPostChanges = async (
 						     page, limit } })
 
 
+export const updatePost = async (
+    post: { id:                     number
+	    versionNo:              number
+	    title:                  string | null
+	    tags:                   string
+	    parentPostIds:          string
+	    originalCreatedFrom:    string | null
+	    originalCreatedBefore:  string | null },
+) =>
+    await apiPut<Post> (
+	`/posts/${ post.id }`,
+	{ version_no: post.versionNo,
+	  title: post.title,
+	  tags: post.tags,
+	  parent_post_ids: post.parentPostIds,
+	  original_created_from: post.originalCreatedFrom,
+	  original_created_before: post.originalCreatedBefore })
+
+
 export const toggleViewedFlg = async (id: string, viewed: boolean): Promise<void> => {
   await (viewed ? apiPost : apiDelete) (`/posts/${ id }/viewed`)
 }
diff --git a/frontend/src/pages/posts/PostHistoryPage.tsx b/frontend/src/pages/posts/PostHistoryPage.tsx
index 2977527..0545b93 100644
--- a/frontend/src/pages/posts/PostHistoryPage.tsx
+++ b/frontend/src/pages/posts/PostHistoryPage.tsx
@@ -11,13 +11,14 @@ import Pagination from '@/components/common/Pagination'
 import MainArea from '@/components/layout/MainArea'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
-import { apiPut } from '@/lib/api'
-import { fetchPostChanges } from '@/lib/posts'
+import { fetchPostChanges, updatePost } from '@/lib/posts'
 import { postsKeys, tagsKeys } from '@/lib/queryKeys'
 import { fetchTag } from '@/lib/tags'
 import { cn, dateString, originalCreatedAtString } from '@/lib/utils'
 
-import type { FC } from 'react'
+import type { FC, MouseEvent } from 'react'
+
+import type { PostVersion } from '@/types'
 
 
 const renderDiff = (diff: { current: string | null; prev: string | null }) => (
@@ -62,6 +63,45 @@ export default (() => {
 
   const qc = useQueryClient ()
 
+  const handleRevert = async (e: MouseEvent<HTMLAnchorElement>, change: PostVersion) => {
+    e.preventDefault ()
+
+    if (!(confirm (`『${ change.title.current || change.url.current }』を版 ${
+		       change.versionNo } に差戻します．\nよろしいですか?`)))
+      return
+
+    try
+    {
+      const id = change.postId
+      const versionNo = change.latestVersionNo + 1
+      const title = change.title.current
+      const tags =
+	  change.tags
+	  .filter (t => t.type !== 'removed')
+	  .map (t => t.name)
+	  .filter (t => t.slice (0, 5) !== 'nico:')
+	  .join (' ')
+      const parentPostIds =
+	  (change.parentPosts ?? [])
+	  .filter (p => p.type !== 'removed')
+	  .map (p => p.id)
+	  .join (' ')
+      const originalCreatedFrom = change.originalCreatedFrom.current
+      const originalCreatedBefore = change.originalCreatedBefore.current
+      await updatePost ({ id, versionNo, title, tags, parentPostIds,
+			  originalCreatedFrom, originalCreatedBefore })
+
+      qc.invalidateQueries ({ queryKey: postsKeys.root })
+      qc.invalidateQueries ({ queryKey: tagsKeys.root })
+
+      toast ({ description: '差戻しました．' })
+    }
+    catch
+    {
+      toast ({ description: '差戻に失敗……' })
+    }
+  }
+
   useEffect (() => {
     document.querySelector ('table')?.scrollIntoView ({ behavior: 'smooth' })
   }, [location.search])
@@ -231,46 +271,7 @@ export default (() => {
 			      {dateString (change.createdAt)}
 			    </td>
 			    <td className="p-2">
-			      <a
-				  href="#"
-				  onClick={async e => {
-				    e.preventDefault ()
-
-				    if (!(confirm (
-					`『${ change.title.current
-					      || change.url.current }』を版 ${
-					change.versionNo } に差戻します．\nよろしいですか?`)))
-				      return
-
-				    try
-				    {
-				      await apiPut (
-					  `/posts/${ change.postId }`,
-					  { title: change.title.current,
-					    tags: change.tags
-						  .filter (t => t.type !== 'removed')
-						  .map (t => t.name)
-						  .filter (t => t.slice (0, 5) !== 'nico:')
-						  .join (' '),
-					    parent_post_ids:
-						(change.parentPosts ?? [])
-						.filter (p => p.type !== 'removed')
-						.map (p => p.id)
-						.join (' '),
-					    original_created_from:
-						change.originalCreatedFrom.current,
-					    original_created_before:
-						change.originalCreatedBefore.current })
-
-				      qc.invalidateQueries ({ queryKey: postsKeys.root })
-				      qc.invalidateQueries ({ queryKey: tagsKeys.root })
-				      toast ({ description: '差戻しました．' })
-				    }
-				    catch
-				    {
-				      toast ({ description: '差戻に失敗……' })
-				    }
-				  }}>
+			      <a href="#" onClick={async e => await handleRevert (e, change)}>
 				復元
 			      </a>
 			    </td>
diff --git a/frontend/src/types.ts b/frontend/src/types.ts
index 5fb8078..e552f69 100644
--- a/frontend/src/types.ts
+++ b/frontend/src/types.ts
@@ -121,6 +121,7 @@ export type Platform = typeof PLATFORMS[number]
 
 export type Post = {
     id:                     number
+    versionNo:              number
     url:                    string
     title:                  string | null
     thumbnail:              string | null
@@ -146,6 +147,7 @@ export type PostTagChange = {
 
 export type PostVersion = {
     postId:                 number
+    latestVersionNo:        number
     versionNo:              number
     eventType:              'create' | 'update' | 'discard' | 'restore'
     title:                  { current: string | null; prev: string | null }