diff --git a/src/heading.ts b/src/heading.ts
index 9014b19..b6a5b0a 100644
--- a/src/heading.ts
+++ b/src/heading.ts
@@ -10,10 +10,14 @@ export class Heading {
     treeLevel: number,
     parent: Heading | null,
   ) {
-    Object.assign(this, {title, hLevel, treeLevel, parent})
+    Object.assign(this, { title, hLevel, treeLevel, parent });
   }
 
   getParent(hLevel: number): Heading | undefined {
     return this.hLevel < hLevel ? this : this.parent?.getParent(hLevel);
   }
+
+  toMarkdown(): string {
+    return `${"\t".repeat(this.treeLevel)}- [ ] ${this.title}`;
+  }
 }
diff --git a/src/plugin.ts b/src/plugin.ts
index 2af4987..77094ad 100644
--- a/src/plugin.ts
+++ b/src/plugin.ts
@@ -75,11 +75,7 @@ export default class OutlineTaskListPlugin extends Plugin {
    * Build the task list from the specified outline.
    */
   static buildTasklist(outline: Outline): string {
-    return outline
-      .map(
-        (heading) => `${"\t".repeat(heading.treeLevel)}- [ ] ${heading.title}`,
-      )
-      .join("\r\n");
+    return outline.map((heading) => heading.toMarkdown()).join("\r\n");
   }
 
   /**