diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index 4ce217f7d..065d89c0b 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -133,11 +133,11 @@ export type CommandSpec = (...args: any[]) => Command
 export type KeyboardShortcutCommand = (props: { editor: Editor }) => boolean
 
 export type Attribute = {
-  default: any
+  default?: any
   rendered?: boolean
   renderHTML?: ((attributes: Record<string, any>) => Record<string, any> | null) | null
   parseHTML?: ((element: HTMLElement) => any | null) | null
-  keepOnSplit: boolean
+  keepOnSplit?: boolean
   isRequired?: boolean
 }