diff --git a/packages/backend/src/core/entities/NoteEntityService.ts b/packages/backend/src/core/entities/NoteEntityService.ts
index e530772dd9..c24c80a5b5 100644
--- a/packages/backend/src/core/entities/NoteEntityService.ts
+++ b/packages/backend/src/core/entities/NoteEntityService.ts
@@ -16,23 +16,13 @@ import { bindThis } from '@/decorators.js';
 import { DebounceLoader } from '@/misc/loader.js';
 import { IdService } from '@/core/IdService.js';
 import { ReactionsBufferingService } from '@/core/ReactionsBufferingService.js';
+import { isPureRenote } from '@/misc/is-renote.js';
 import type { OnModuleInit } from '@nestjs/common';
 import type { CustomEmojiService } from '../CustomEmojiService.js';
 import type { ReactionService } from '../ReactionService.js';
 import type { UserEntityService } from './UserEntityService.js';
 import type { DriveFileEntityService } from './DriveFileEntityService.js';
 
-function isPureRenote(note: MiNote): note is MiNote & { renoteId: MiNote['id']; renote: MiNote } {
-	return (
-		note.renote != null &&
-		note.reply == null &&
-		note.text == null &&
-		note.cw == null &&
-		(note.fileIds == null || note.fileIds.length === 0) &&
-		!note.hasPoll
-	);
-}
-
 function getAppearNoteIds(notes: MiNote[]): Set<string> {
 	const appearNoteIds = new Set<string>();
 	for (const note of notes) {
diff --git a/packages/backend/src/misc/is-renote.ts b/packages/backend/src/misc/is-renote.ts
index 48f821806c..245057c64e 100644
--- a/packages/backend/src/misc/is-renote.ts
+++ b/packages/backend/src/misc/is-renote.ts
@@ -36,6 +36,17 @@ export function isQuote(note: Renote): note is Quote {
 		note.fileIds.length > 0;
 }
 
+export function isPureRenote(note: MiNote): note is MiNote & { renoteId: MiNote['id']; renote: MiNote } {
+	return (
+		note.renote != null &&
+		note.reply == null &&
+		note.text == null &&
+		note.cw == null &&
+		(note.fileIds == null || note.fileIds.length === 0) &&
+		!note.hasPoll
+	);
+}
+
 type PackedRenote =
 	Packed<'Note'> & {
 		renoteId: NonNullable<Packed<'Note'>['renoteId']>