diff --git a/packages/core/src/comments/index.ts b/packages/core/src/comments/index.ts
index cba1a7a30..101fbafc1 100644
--- a/packages/core/src/comments/index.ts
+++ b/packages/core/src/comments/index.ts
@@ -7,3 +7,4 @@ export * from "./threadstore/yjs/RESTYjsThreadStore.js";
 export * from "./threadstore/yjs/YjsThreadStore.js";
 export * from "./threadstore/yjs/YjsThreadStoreBase.js";
 export * from "./types.js";
+export { CommentMark } from "../extensions/Comments/CommentMark.js";