diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index a8a7f665..d97ec291 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -66,6 +66,11 @@ export type JSONContent = {
   type: string,
   attrs?: Record<string, any>,
   content?: JSONContent[],
+  marks?: {
+    type: string,
+    attrs?: Record<string, any>,
+    [key: string]: any,
+  }[],
   text?: string,
   [key: string]: any,
 }