diff --git a/frontend/src/components/PostEditForm.tsx b/frontend/src/components/PostEditForm.tsx
index 302c2d1..f598bec 100644
--- a/frontend/src/components/PostEditForm.tsx
+++ b/frontend/src/components/PostEditForm.tsx
@@ -155,16 +155,14 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
     {
       const titleMissing = !title?.trim ()
       const thumbnailMissing =
-	  !(post.thumbnail?.trim () || post.thumbnailBase?.trim ())
+	  !titleMissing
+	  && !(post.thumbnail?.trim () || post.thumbnailBase?.trim ())
 
       if ((titleMissing || thumbnailMissing)
 	  && !(await dialogue.confirm ({
 	      title: titleMissing
 		  ? label ('edit.titleMissingConfirmation')
-		  : label ('shared:labels.thumbnailMissing'),
-	      description: (titleMissing && thumbnailMissing)
-		  ? label ('shared:labels.thumbnailMissing')
-		  : undefined,
+		  : label ('edit.thumbnailMissingConfirmation'),
 	      confirmText: label ('shared:actions.update'),
 	      cancelText: label ('shared:actions.cancel'),
 	      closeLabel: label ('settings:actions.close') })))
diff --git a/frontend/src/locales/ain-Kana/posts.json b/frontend/src/locales/ain-Kana/posts.json
index 9001c2f..6ad0578 100644
--- a/frontend/src/locales/ain-Kana/posts.json
+++ b/frontend/src/locales/ain-Kana/posts.json
@@ -1,5 +1,5 @@
 {
-  "_untranslated": ["edit.titleMissingConfirmation"],
+  "_untranslated": ["edit.titleMissingConfirmation", "edit.thumbnailMissingConfirmation"],
   "list": {
     "tagline": "{{brand}}",
     "empty": "ミンタㇻ　タ　ネン　カ　イサㇺ",
@@ -33,6 +33,7 @@
   },
   "edit": {
     "titleMissingConfirmation": "タイトルが設定されてゐません．更新しますか?",
+    "thumbnailMissingConfirmation": "サムネールが設定されてゐません．更新しますか?",
     "validationFailed": "アシㇼ　カㇻ　カ　エアイカㇷ゚……",
     "conflictTitle": "モㇱマ　クㇽ　アシㇼ　カㇻ　ワ　アン！",
     "conflictDescription": "モㇱマ　イカㇻ　クㇽ　エエトコ　アシㇼ　カㇻ　ワ　アン。",
diff --git a/frontend/src/locales/ja/posts.json b/frontend/src/locales/ja/posts.json
index 209d390..196289b 100644
--- a/frontend/src/locales/ja/posts.json
+++ b/frontend/src/locales/ja/posts.json
@@ -23,6 +23,7 @@
   },
   "edit": {
     "titleMissingConfirmation": "タイトルが設定されてゐません．更新しますか?",
+    "thumbnailMissingConfirmation": "サムネールが設定されてゐません．更新しますか?",
     "validationFailed": "更新はできなかったよ……",
     "conflictTitle": "競合が発生しました．",
     "conflictDescription": "ほかの耕作員が先に更新してゐます．",