diff --git a/packages/backend/src/config.ts b/packages/backend/src/config.ts
index f263c4d06b06..cb92bd877920 100644
--- a/packages/backend/src/config.ts
+++ b/packages/backend/src/config.ts
@@ -100,6 +100,7 @@ type Source = {
 		maxWebImageSize?: number;
 		withRepliesInHomeTL?: boolean;
 		withRepliesInUserList?: boolean;
+		blockMentionsFromUnfamiliarRemoteUsers?: boolean;
 	}
 };
 
@@ -185,6 +186,7 @@ export type Config = {
 		maxWebImageSize?: number;
 		withRepliesInHomeTL?: boolean,
 		withRepliesInUserList: boolean,
+		blockMentionsFromUnfamiliarRemoteUsers: boolean;
 	}
 };
 
@@ -230,6 +232,7 @@ export function loadConfig(): Config {
 		// to avoid merge conflict in the future, this is at top
 		nirila: Object.assign({
 			withRepliesInUserList: true,
+			blockMentionsFromUnfamiliarRemoteUsers: false,
 		}, config.nirila ?? {}),
 		version,
 		publishTarballInsteadOfProvideRepositoryUrl: !!config.publishTarballInsteadOfProvideRepositoryUrl,
diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index ff3e10e43b20..5297f1e2d3e6 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -368,7 +368,7 @@ export class NoteCreateService implements OnApplicationShutdown {
 
 		const willCauseNotification = mentionedUsers.filter(u => u.host === null).length > 0 || data.reply?.userHost === null || data.renote?.userHost === null;
 
-		if (process.env.MISSKEY_BLOCK_MENTIONS_FROM_UNFAMILIAR_REMOTE_USERS === 'true' && user.host !== null && willCauseNotification) {
+		if (this.config.nirila.blockMentionsFromUnfamiliarRemoteUsers && user.host !== null && willCauseNotification) {
 			const userEntity = await this.usersRepository.findOneBy({ id: user.id });
 			if ((userEntity?.followersCount ?? 0) === 0) {
 				this.logger.error('Request rejected because user has no local followers', { user: user.id, note: data });