diff --git a/index.d.ts b/index.d.ts
index 26a13a4..facb0ca 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,8 +1,8 @@
 declare global {
-    export interface CollectionDocument {
+    export type CollectionDocument<T = {}, D = Date> = T & {
         id?: string
-        insertTime?: Date
-        updateTime?: Date
+        insertTime?: D
+        updateTime?: D
         [key: string]: any
     }