diff --git a/examples/demo/App.tsx b/examples/demo/App.tsx
index e0815291..1d11512d 100755
--- a/examples/demo/App.tsx
+++ b/examples/demo/App.tsx
@@ -514,7 +514,7 @@ function TabStorage({tab, layout}: {tab: TabNode, layout: FlexLayout.Layout}) {
                         width: listBounds.width,
                         height: listBounds.height,
                         callback: () => {
-                            const json = dragging instanceof TabNode ? dragging._toJson() as IJsonTabNode : dragging
+                            const json = dragging instanceof TabNode ? dragging.toJson() as IJsonTabNode : dragging
 
                             setStoredTabs(tabs => [...tabs, json])
 
@@ -541,7 +541,7 @@ function TabStorage({tab, layout}: {tab: TabNode, layout: FlexLayout.Layout}) {
                                 width: itemRect.width,
                                 height: 0,
                                 callback: () => {
-                                    const json = dragging instanceof TabNode ? dragging._toJson() as IJsonTabNode : dragging
+                                    const json = dragging instanceof TabNode ? dragging.toJson() as IJsonTabNode : dragging
 
                                     setStoredTabs(tabs => {
                                         const newTabs = [...tabs]
diff --git a/src/model/BorderNode.ts b/src/model/BorderNode.ts
index fceae400..015c92ec 100755
--- a/src/model/BorderNode.ts
+++ b/src/model/BorderNode.ts
@@ -6,6 +6,7 @@ import Orientation from "../Orientation";
 import Rect from "../Rect";
 import IDraggable from "./IDraggable";
 import IDropTarget from "./IDropTarget";
+import { IJsonBorderNode } from "./IJsonModel";
 import Model, { ILayoutMetrics } from "./Model";
 import Node from "./Node";
 import SplitterNode from "./SplitterNode";
@@ -355,12 +356,11 @@ class BorderNode extends Node implements IDropTarget {
         this._model._tidy();
     }
 
-    /** @hidden @internal */
-    _toJson() {
+    toJson(): IJsonBorderNode {
         const json: any = {};
         BorderNode._attributeDefinitions.toJson(json, this._attributes);
         json.location = this._location.getName();
-        json.children = this._children.map((child) => (child as TabNode)._toJson());
+        json.children = this._children.map((child) => (child as TabNode).toJson());
         return json;
     }
 
diff --git a/src/model/BorderSet.ts b/src/model/BorderSet.ts
index ba40c8f6..9c959673 100755
--- a/src/model/BorderSet.ts
+++ b/src/model/BorderSet.ts
@@ -40,7 +40,7 @@ class BorderSet {
 
     /** @hidden @internal */
     _toJson() {
-        return this._borders.map((borderNode) => borderNode._toJson());
+        return this._borders.map((borderNode) => borderNode.toJson());
     }
 
     /** @hidden @internal */
diff --git a/src/model/Model.ts b/src/model/Model.ts
index 00c90e68..8691bb43 100755
--- a/src/model/Model.ts
+++ b/src/model/Model.ts
@@ -385,17 +385,15 @@ class Model {
      * @returns {IJsonModel} json object that represents this model
      */
     toJson(): IJsonModel {
-        const json: any = { global: {}, layout: {} };
-        Model._attributeDefinitions.toJson(json.global, this._attributes);
+        const global: any = {};
+        Model._attributeDefinitions.toJson(global, this._attributes);
 
         // save state of nodes
         this.visitNodes((node) => {
             node._fireEvent("save", undefined);
         });
 
-        json.borders = this._borders._toJson();
-        json.layout = (this._root as RowNode)._toJson();
-        return json as IJsonModel;
+        return { global, borders: this._borders._toJson(), layout: (this._root as RowNode).toJson() };
     }
 
     getSplitterSize() {
diff --git a/src/model/Node.ts b/src/model/Node.ts
index 49c2283f..3feace83 100755
--- a/src/model/Node.ts
+++ b/src/model/Node.ts
@@ -4,6 +4,7 @@ import DropInfo from "../DropInfo";
 import Orientation from "../Orientation";
 import Rect from "../Rect";
 import IDraggable from "./IDraggable";
+import { IJsonBorderNode, IJsonRowNode, IJsonTabNode, IJsonTabSetNode } from "./IJsonModel";
 import Model, { ILayoutMetrics } from "./Model";
 
 abstract class Node {
@@ -92,6 +93,8 @@ abstract class Node {
         delete this._listeners[event];
     }
 
+    abstract toJson(): IJsonRowNode | IJsonBorderNode | IJsonTabSetNode | IJsonTabNode | undefined;
+
     /** @hidden @internal */
     _setId(id: string) {
         this._attributes.id = id;
@@ -283,8 +286,6 @@ abstract class Node {
     abstract _updateAttrs(json: any): void;
     /** @hidden @internal */
     abstract _getAttributeDefinitions(): AttributeDefinitions;
-    /** @hidden @internal */
-    abstract _toJson(): any;
 }
 
 export default Node;
diff --git a/src/model/RowNode.ts b/src/model/RowNode.ts
index 0e731377..0c438cbc 100755
--- a/src/model/RowNode.ts
+++ b/src/model/RowNode.ts
@@ -8,6 +8,7 @@ import Rect from "../Rect";
 import BorderNode from "./BorderNode";
 import IDraggable from "./IDraggable";
 import IDropTarget from "./IDropTarget";
+import { IJsonRowNode } from "./IJsonModel";
 import Model, { ILayoutMetrics } from "./Model";
 import Node from "./Node";
 import SplitterNode from "./SplitterNode";
@@ -506,14 +507,13 @@ class RowNode extends Node implements IDropTarget {
         this._model._tidy();
     }
 
-    /** @hidden @internal */
-    _toJson() {
+    toJson(): IJsonRowNode {
         const json: any = {};
         RowNode._attributeDefinitions.toJson(json, this._attributes);
 
         json.children = [];
         this._children.forEach((child) => {
-            json.children.push(child._toJson());
+            json.children.push(child.toJson());
         });
 
         return json;
diff --git a/src/model/SplitterNode.ts b/src/model/SplitterNode.ts
index e0ea0be9..fa897acf 100755
--- a/src/model/SplitterNode.ts
+++ b/src/model/SplitterNode.ts
@@ -72,8 +72,7 @@ class SplitterNode extends Node {
         return new AttributeDefinitions();
     }
 
-    /** @hidden @internal */
-    _toJson(): any {
+    toJson(): undefined {
         return undefined;
     }
 }
diff --git a/src/model/TabNode.ts b/src/model/TabNode.ts
index 39acbb43..a9ec8b87 100755
--- a/src/model/TabNode.ts
+++ b/src/model/TabNode.ts
@@ -3,6 +3,7 @@ import AttributeDefinitions from "../AttributeDefinitions";
 import Rect from "../Rect";
 import BorderNode from "./BorderNode";
 import IDraggable from "./IDraggable";
+import { IJsonTabNode } from "./IJsonModel";
 import Model, { ILayoutMetrics } from "./Model";
 import Node from "./Node";
 import TabSetNode from "./TabSetNode";
@@ -174,8 +175,7 @@ class TabNode extends Node implements IDraggable {
         this._fireEvent("close", {});
     }
 
-    /** @hidden @internal */
-    _toJson() {
+    toJson(): IJsonTabNode {
         const json = {};
         TabNode._attributeDefinitions.toJson(json, this._attributes);
         return json;
diff --git a/src/model/TabSetNode.ts b/src/model/TabSetNode.ts
index 8ad1e5f3..cd9623d9 100755
--- a/src/model/TabSetNode.ts
+++ b/src/model/TabSetNode.ts
@@ -7,6 +7,7 @@ import Rect from "../Rect";
 import BorderNode from "./BorderNode";
 import IDraggable from "./IDraggable";
 import IDropTarget from "./IDropTarget";
+import { IJsonTabSetNode } from "./IJsonModel";
 import Model, { ILayoutMetrics } from "./Model";
 import Node from "./Node";
 import RowNode from "./RowNode";
@@ -430,11 +431,10 @@ class TabSetNode extends Node implements IDraggable, IDropTarget {
         this._model._tidy();
     }
 
-    /** @hidden @internal */
-    _toJson(): any {
+    toJson(): IJsonTabSetNode {
         const json: any = {};
         TabSetNode._attributeDefinitions.toJson(json, this._attributes);
-        json.children = this._children.map((child) => child._toJson());
+        json.children = this._children.map((child) => child.toJson());
 
         if (this.isActive()) {
             json.active = true;