diff --git a/src/cubismdefaultparameterid.ts b/src/cubismdefaultparameterid.ts
index afc8260..1d716d5 100644
--- a/src/cubismdefaultparameterid.ts
+++ b/src/cubismdefaultparameterid.ts
@@ -10,9 +10,7 @@
  *         デフォルト値の仕様は以下のマニュアルに基づく<br>
  *         https://docs.live2d.com/cubism-editor-manual/standard-parametor-list/
  */
-export const CubismDefaultParameterId = Object.freeze<{
-  [key: string]: string;
-}>({
+export const CubismDefaultParameterId = Object.freeze<Record<string, string>>({
   // パーツID
   HitAreaPrefix: 'HitArea',
   HitAreaHead: 'Head',
diff --git a/src/live2dcubismframework.ts b/src/live2dcubismframework.ts
index 6413da3..17dcefb 100644
--- a/src/live2dcubismframework.ts
+++ b/src/live2dcubismframework.ts
@@ -54,7 +54,7 @@ let s_cubismIdManager: CubismIdManager = null;
 /**
  * Framework内で使う定数の宣言
  */
-export const Constant = Object.freeze<{ [key: string]: number }>({
+export const Constant = Object.freeze<Record<string, number>>({
   vertexOffset: 0, // メッシュ頂点のオフセット値
   vertexStep: 2 // メッシュ頂点のステップ値
 });