diff --git a/packages/misskey-js/src/api.ts b/packages/misskey-js/src/api.ts
index 17de317d19..974cb35ace 100644
--- a/packages/misskey-js/src/api.ts
+++ b/packages/misskey-js/src/api.ts
@@ -49,7 +49,7 @@ export class APIClient {
 		this.credential = opts.credential;
 		// ネイティブ関数をそのまま変数に代入して使おうとするとChromiumではIllegal invocationエラーが発生するため、
 		// 環境で実装されているfetchを使う場合は無名関数でラップして使用する
-		this.fetch = opts.fetch || ((...args) => fetch(...args));
+		this.fetch = opts.fetch ?? ((...args) => fetch(...args));
 	}
 
 	public request<E extends keyof Endpoints, P extends Endpoints[E]['req']>(
diff --git a/packages/misskey-js/src/streaming.ts b/packages/misskey-js/src/streaming.ts
index 9dd764952e..d97c2182fd 100644
--- a/packages/misskey-js/src/streaming.ts
+++ b/packages/misskey-js/src/streaming.ts
@@ -36,7 +36,7 @@ export default class Stream extends EventEmitter<StreamEvents> {
 		WebSocket?: any;
 	}) {
 		super();
-		options = options || { };
+		options = options ?? { };
 
 		const query = urlQuery({
 			i: user?.token,