diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index 2055a0d21..939662707 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -368,6 +368,14 @@ export class NoteCreateService implements OnApplicationShutdown {
 			}
 		}
 
+		if (user.host && !data.cw) {
+			await this.federatedInstanceService.fetch(user.host).then(async i => {
+				if (i.isNSFW) {
+					data.cw = 'Instance is marked as NSFW';
+				}
+			});
+		}
+
 		const note = await this.insertNote(user, data, tags, emojis, mentionedUsers);
 
 		setImmediate('post created', { signal: this.#shutdownController.signal }).then(