diff --git a/types/slate/index.d.ts b/types/slate/index.d.ts
index 2538bea6f9..1f17afe93f 100644
--- a/types/slate/index.d.ts
+++ b/types/slate/index.d.ts
@@ -327,6 +327,7 @@ export interface LeafProperties {
 export interface LeafJSON {
     marks?: MarkJSON[];
     text?: string;
+    object: "leaf";
 }
 
 export class Leaf extends Immutable.Record({}) {
@@ -521,6 +522,7 @@ export interface MarkProperties {
 export interface MarkJSON {
     type: string;
     data?: { [key: string]: any };
+    object: "mark";
 }
 
 export class Mark extends Immutable.Record({}) {
diff --git a/types/slate/slate-tests.ts b/types/slate/slate-tests.ts
index 344d4da3ee..07f15dcaac 100644
--- a/types/slate/slate-tests.ts
+++ b/types/slate/slate-tests.ts
@@ -12,10 +12,12 @@ const node: BlockJSON = {
 			key: "a",
 			leaves: [
 				{
+                    object: "leaf",
 					text: "example",
 					marks: [{
                         data: { testData: "data"},
-                        type: "mark"
+                        type: "mark",
+                        object: "mark"
                     }]
 				}
 			]