diff --git a/package.json b/package.json
index e3afaa2b..87bf2273 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mind-elixir",
-  "version": "3.0.1",
+  "version": "3.0.2",
   "type": "module",
   "description": "Mind elixir is a free open source mind map core.",
   "keywords": [
diff --git a/src/index.ts b/src/index.ts
index 02bb5f89..3dfac727 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -130,7 +130,7 @@ MindElixir.DARK_THEME = DARK_THEME
  * @memberof MindElixir
  * @static
  */
-MindElixir.version = '3.0.1'
+MindElixir.version = '3.0.2'
 /**
  * @function
  * @memberof MindElixir
diff --git a/src/interact.ts b/src/interact.ts
index e649e064..fc2521ee 100644
--- a/src/interact.ts
+++ b/src/interact.ts
@@ -319,9 +319,8 @@ export const expandNode = function (this: MindElixirInstance, el: Topic, isExpan
  * @param {TargetElement} data mind elixir data
  */
 export const refresh = function (this: MindElixirInstance, data?: MindElixirData) {
-  data = JSON.parse(JSON.stringify(data)) // it shouldn't contanimate the original data
-  // add parent property to every node
   if (data) {
+    data = JSON.parse(JSON.stringify(data)) as MindElixirData // it shouldn't contanimate the original data
     this.nodeData = data.nodeData
     this.linkData = data.linkData || {}
   }
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 026a0997..5d9a78e2 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -21,6 +21,9 @@ export const getObjById = function (id: string, data: NodeObj): NodeObj | null {
   }
 }
 
+/**
+ * Add parent property to every node
+ */
 export const fillParent = (data: NodeObj, parent?: NodeObj) => {
   data.parent = parent
   if (data.children) {