diff --git a/src/services/export/zip.ts b/src/services/export/zip.ts
index bcf07c876..f6ffb45d1 100644
--- a/src/services/export/zip.ts
+++ b/src/services/export/zip.ts
@@ -21,6 +21,7 @@ import type AttributeMeta from "../meta/attribute_meta.js";
 import type BBranch from "../../becca/entities/bbranch.js";
 import type { Response } from "express";
 import { RESOURCE_DIR } from "../resource_dir.js";
+import type { NoteMetaFile } from "../meta/note_meta.js";
 
 async function exportToZip(taskContext: TaskContext, branch: BBranch, format: "html" | "markdown", res: Response | fs.WriteStream, setHeaders = true) {
     if (!["html", "markdown"].includes(format)) {
@@ -485,8 +486,11 @@ ${markdownContent}`;
 
     const existingFileNames: Record<string, number> = format === "html" ? { navigation: 0, index: 1 } : {};
     const rootMeta = createNoteMeta(branch, { notePath: [] }, existingFileNames);
+    if (!rootMeta) {
+        throw new Error("Unable to create root meta.");
+    }
 
-    const metaFile = {
+    const metaFile: NoteMetaFile = {
         formatVersion: 2,
         appVersion: packageInfo.version,
         files: [rootMeta]
diff --git a/src/services/meta/note_meta.ts b/src/services/meta/note_meta.ts
index 79d2e4cd2..0aaafb6b5 100644
--- a/src/services/meta/note_meta.ts
+++ b/src/services/meta/note_meta.ts
@@ -1,6 +1,12 @@
 import type AttachmentMeta from "./attachment_meta.js";
 import type AttributeMeta from "./attribute_meta.js";
 
+export interface NoteMetaFile {
+    formatVersion: number;
+    appVersion: string;
+    files: NoteMeta[];
+}
+
 export default interface NoteMeta {
     noteId?: string;
     notePath?: string[];