diff --git a/dist/deep-copy.d.ts b/dist/deep-copy.d.ts
new file mode 100644
index 0000000..45c26a1
--- /dev/null
+++ b/dist/deep-copy.d.ts
@@ -0,0 +1,10 @@
+/**
+ * Deep copy the given object considering circular structure.
+ * This function caches all nested objects and its copies.
+ * If it detects circular structure, use cached copy to avoid infinite loop.
+ *
+ * @param {*} obj
+ * @param {Array<Object>} cache
+ * @return {*}
+ */
+export declare function deepCopy<T>(obj: T, cache?: any[]): T;
diff --git a/dist/deep-copy.js b/dist/deep-copy.js
index d770708..4d0abb6 100644
--- a/dist/deep-copy.js
+++ b/dist/deep-copy.js
@@ -1,5 +1,6 @@
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
+exports.deepCopy = void 0;
 /** from  https://github.com/vuejs/vuex/blob/dev/src/util.js
  * Get the first item that pass the test
  * by second argument function
@@ -41,4 +42,3 @@ function deepCopy(obj, cache) {
     return copy;
 }
 exports.deepCopy = deepCopy;
-//# sourceMappingURL=deep-copy.js.map
\ No newline at end of file
diff --git a/dist/deep-copy.js.map b/dist/deep-copy.js.map
deleted file mode 100644
index 92e5367..0000000
--- a/dist/deep-copy.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"deep-copy.js","sourceRoot":"","sources":["../src/deep-copy.ts"],"names":[],"mappings":";;AAAA;;;;;;;GAOG;AACH,cAAc,IAAI,EAAE,CAAC;IACjB,MAAM,CAAC,IAAI,CAAC,MAAM,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC;AAC7B,CAAC;AAED;;;;;;;;GAQG;AACH,kBAA4B,GAAM,EAAE,KAAU;IAAV,sBAAA,EAAA,UAAU;IAC1C,wCAAwC;IACxC,EAAE,CAAC,CAAC,GAAG,KAAK,IAAI,IAAI,OAAO,GAAG,KAAK,QAAQ,CAAC,CAAC,CAAC;QAC1C,MAAM,CAAC,GAAG,CAAC;IACf,CAAC;IAED,6CAA6C;IAC7C,IAAM,GAAG,GAAG,IAAI,CAAC,KAAK,EAAE,UAAA,CAAC,IAAI,OAAA,CAAC,CAAC,QAAQ,KAAK,GAAG,EAAlB,CAAkB,CAAC,CAAC;IACjD,EAAE,CAAC,CAAC,GAAG,CAAC,CAAC,CAAC;QACN,MAAM,CAAC,GAAG,CAAC,IAAI,CAAC;IACpB,CAAC;IAED,IAAM,IAAI,GAAG,KAAK,CAAC,OAAO,CAAC,GAAG,CAAC,GAAG,EAAE,GAAG,EAAE,CAAC;IAC1C,mCAAmC;IACnC,oDAAoD;IACpD,KAAK,CAAC,IAAI,CAAC,EAAE,QAAQ,EAAE,GAAG,EAAE,IAAI,MAAA,EAAE,CAAC,CAAC;IAEpC,MAAM,CAAC,IAAI,CAAC,GAAG,CAAC,CAAC,OAAO,CAAC,UAAA,GAAG;QACxB,IAAI,CAAC,GAAG,CAAC,GAAG,QAAQ,CAAC,GAAG,CAAC,GAAG,CAAC,EAAE,KAAK,CAAC,CAAC;IAC1C,CAAC,CAAC,CAAC;IAEH,MAAM,CAAI,IAAI,CAAC;AACnB,CAAC;AAtBD,4BAsBC"}
\ No newline at end of file
diff --git a/dist/test.d.ts b/dist/test.d.ts
new file mode 100644
index 0000000..cb0ff5c
--- /dev/null
+++ b/dist/test.d.ts
@@ -0,0 +1 @@
+export {};
diff --git a/dist/test.js b/dist/test.js
index 7723e34..ff6c3a1 100644
--- a/dist/test.js
+++ b/dist/test.js
@@ -5,8 +5,7 @@ var a = { dataA: 10, b: null };
 var b = { dataB: 20, a: null };
 a.b = b;
 b.a = a;
-var newA = deep_copy_1.deepCopy(a);
+var newA = (0, deep_copy_1.deepCopy)(a);
 console.log(newA.dataA === 10); //true
 console.log(newA.b.dataB === 20); //true
 console.log(newA.b.a === newA); //true
-//# sourceMappingURL=test.js.map
\ No newline at end of file
diff --git a/dist/test.js.map b/dist/test.js.map
deleted file mode 100644
index 2437fbb..0000000
--- a/dist/test.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"test.js","sourceRoot":"","sources":["../src/test.ts"],"names":[],"mappings":";;AAAA,yCAAuC;AAEvC,IAAI,CAAC,GAAG,EAAE,KAAK,EAAE,EAAE,EAAE,CAAC,EAAE,IAAI,EAAE,CAAC;AAC/B,IAAI,CAAC,GAAG,EAAE,KAAK,EAAE,EAAE,EAAE,CAAC,EAAE,IAAI,EAAE,CAAC;AAC/B,CAAC,CAAC,CAAC,GAAG,CAAC,CAAC;AACR,CAAC,CAAC,CAAC,GAAG,CAAC,CAAC;AAER,IAAI,IAAI,GAAG,oBAAQ,CAAC,CAAC,CAAC,CAAC;AACvB,OAAO,CAAC,GAAG,CAAC,IAAI,CAAC,KAAK,KAAK,EAAE,CAAC,CAAC,CAAK,MAAM;AAC1C,OAAO,CAAC,GAAG,CAAC,IAAI,CAAC,CAAC,CAAC,KAAK,KAAK,EAAE,CAAC,CAAC,CAAG,MAAM;AAC1C,OAAO,CAAC,GAAG,CAAC,IAAI,CAAC,CAAC,CAAC,CAAC,KAAK,IAAI,CAAC,CAAC,CAAK,MAAM"}
\ No newline at end of file
diff --git a/package.json b/package.json
index fee89d2..bce8645 100644
--- a/package.json
+++ b/package.json
@@ -1,15 +1,18 @@
 {
   "name": "fast-deep-copy",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "20 lines code! Deep copy the given object considering circular structure",
   "main": "dist/deep-copy.js",
+  "types": "dist/deep-copy.d.ts",
   "keywords": [
     "fast-deep-copy",
     "deep-copy",
     "deepcopy"
   ],
   "scripts": {
-    "test": "node dist/test.js"
+    "test": "node dist/test.js",
+    "build": "tsc",
+    "desc": "tsc --project ./tsconfig.desc.json"
   },
   "author": "625335512@qq.com",
   "homepage": "https://github.com/zhaolihang/fast-deep-copy",
diff --git a/readme.md b/readme.md
index afc6ae1..f023e4b 100644
--- a/readme.md
+++ b/readme.md
@@ -1,5 +1,6 @@
 #   fast-deep-copy 
     Only 20 lines code! no deps!
+    It can correctly handle circular references!
 
 ##  Useage:
 ```
diff --git a/tsconfig.desc.json b/tsconfig.desc.json
new file mode 100644
index 0000000..6a51567
--- /dev/null
+++ b/tsconfig.desc.json
@@ -0,0 +1,15 @@
+{
+    "compileOnSave": true,
+    "compilerOptions": {
+        "module": "commonjs",
+        "target": "es5",
+        "sourceMap": false,
+        "declaration": true,
+        "allowJs": true,
+        "moduleResolution": "node",
+        "outDir": "dist"
+    },
+    "include": [
+        "src/**/*"
+    ]
+}
\ No newline at end of file
diff --git a/tsconfig.json b/tsconfig.json
index 7a83bd5..21e8176 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,14 +1,14 @@
- {
-     "compileOnSave": true,
-     "compilerOptions": {
-         "module": "commonjs",
-         "target": "es5",
-         "sourceMap": true,
-         "allowJs":true,
-         "moduleResolution": "node",
-         "outDir": "dist"         
-     },
-     "include": [
-         "src/**/*"
-     ]
- }
\ No newline at end of file
+{
+    "compileOnSave": true,
+    "compilerOptions": {
+        "module": "commonjs",
+        "target": "es5",
+        "sourceMap": false,
+        "allowJs": true,
+        "moduleResolution": "node",
+        "outDir": "dist"
+    },
+    "include": [
+        "src/**/*"
+    ]
+}
\ No newline at end of file