diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index 9691c014a..2071e61ed 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -88,7 +88,7 @@ export interface EditorOptions {
 export type HTMLContent = string
 
 export type JSONContent = {
-  type: string,
+  type?: string,
   attrs?: Record<string, any>,
   content?: JSONContent[],
   marks?: {