diff --git a/index.d.ts b/index.d.ts
index 74e9203..497501c 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -27,10 +27,10 @@ declare namespace FastCopy {
   };
 }
 
-declare function copy<T>(object: any, options?: FastCopy.Options): T;
+declare function copy<T>(object: T, options?: FastCopy.Options): T;
 
 declare namespace copy {
-  function strictCopy<T>(object: any, options?: FastCopy.Options): T;
+  function strictCopy<T>(object: T, options?: FastCopy.Options): T;
 }
 
 export default copy;