diff --git a/src/services/export/zip.ts b/src/services/export/zip.ts
index f6ffb45d1..a21572b04 100644
--- a/src/services/export/zip.ts
+++ b/src/services/export/zip.ts
@@ -407,6 +407,10 @@ ${markdownContent}`;
     }
 
     function saveNavigation(rootMeta: NoteMeta, navigationMeta: NoteMeta) {
+        if (!navigationMeta.dataFileName) {
+            return;
+        }
+
         function saveNavigationInner(meta: NoteMeta) {
             let html = "<li>";
 
@@ -451,6 +455,10 @@ ${markdownContent}`;
         let firstNonEmptyNote;
         let curMeta = rootMeta;
 
+        if (!indexMeta.dataFileName) {
+            return;
+        }
+
         while (!firstNonEmptyNote) {
             if (curMeta.dataFileName && curMeta.noteId) {
                 firstNonEmptyNote = getNoteTargetUrl(curMeta.noteId, rootMeta);
@@ -479,6 +487,10 @@ ${markdownContent}`;
     }
 
     function saveCss(rootMeta: NoteMeta, cssMeta: NoteMeta) {
+        if (!cssMeta.dataFileName) {
+            return;
+        }
+
         const cssContent = fs.readFileSync(`${RESOURCE_DIR}/libraries/ckeditor/ckeditor-content.css`);
 
         archive.append(cssContent, { name: cssMeta.dataFileName });
diff --git a/src/services/utils.spec.ts b/src/services/utils.spec.ts
index 3451a881d..a509b2b0a 100644
--- a/src/services/utils.spec.ts
+++ b/src/services/utils.spec.ts
@@ -167,12 +167,12 @@ describe("#getContentDisposition", () => {
     const defaultFallBackDisposition = `file; filename="file"; filename*=UTF-8''file`;
     const testCases: TestCase<typeof utils.getContentDisposition>[] = [
         [
-            "when passed filename is empty, it should fallback to default value 'file'", 
+            "when passed filename is empty, it should fallback to default value 'file'",
             [" "],
             defaultFallBackDisposition
         ],
         [
-            "when passed filename '..' would cause sanitized filename to be empty, it should fallback to default value 'file'", 
+            "when passed filename '..' would cause sanitized filename to be empty, it should fallback to default value 'file'",
             [".."],
             defaultFallBackDisposition
         ],
@@ -304,19 +304,16 @@ describe("#getNoteTitle", () => {
         ],
         [
           "when a noteMeta object is passed, it should use the title from the noteMeta, if present",
-          //@ts-expect-error - passing in incomplete noteMeta - but we only care about the title prop here
           ["test_file.md", true, { title: "some other title"}],
           "some other title"
         ],
         [
           "when a noteMeta object is passed, but the title prop is empty, it should try to handle the filename as if no noteMeta was passed",
-          //@ts-expect-error - passing in incomplete noteMeta - but we only care about the title prop here
           ["test_file.md", true, { title: ""}],
           "test file"
         ],
         [
             "when a noteMeta object is passed, but the title prop is empty, it should try to handle the filename as if no noteMeta was passed",
-            //@ts-expect-error - passing in incomplete noteMeta - but we only care about the title prop here
             ["test_file.json", false, { title: " "}],
             "test_file.json"
         ]
@@ -627,4 +624,4 @@ describe("#formatDownloadTitle", () => {
             expect(actual).toStrictEqual(expected);
         });
     });
-});
\ No newline at end of file
+});