diff --git a/src/parsing.ts b/src/parsing.ts
index 5dcc985..2c73d0d 100644
--- a/src/parsing.ts
+++ b/src/parsing.ts
@@ -408,7 +408,7 @@ export class SupernoteX implements ISupernote {
 
 	/** Parse Supernote file signature from buffer. */
 	_parseSignature(buffer: Uint8Array): string {
-		const pattern = /^noteSN_FILE_VER_(\d{8})/;
+		const pattern = /^(?:mark|note)SN_FILE_VER_(\d{8})/;
 		const content = uint8ArrayToString(buffer, 'utf8', 0, 24);
 		const match = content.match(pattern);
 		if (!match)
diff --git a/tests/input/digest_test.mark b/tests/input/digest_test.mark
new file mode 100644
index 0000000..262fe9f
Binary files /dev/null and b/tests/input/digest_test.mark differ
diff --git a/tests/main.test.ts b/tests/main.test.ts
index b7b9a16..7141178 100644
--- a/tests/main.test.ts
+++ b/tests/main.test.ts
@@ -64,6 +64,17 @@ describe("links", () => {
   })
 })
 
+describe("digest_image", () => {
+  test("convert a mark file into a png image", { timeout: 30000 }, async () => {
+    const sn = new SupernoteX(await readFileToUint8Array("digest_test.mark"))
+    const images = await toImage(sn)
+    expect(images).not.toBeUndefined()
+    for await (const [index, image] of images.entries()) {
+      await imagejs.writeSync(`tests/output/digest_test.mark-${index}.png`, image)
+    }
+  })
+})
+
 describe("nomad", () => {
   test("convert a note from a nomad Chauvet 3.15.27 to png pages", { timeout: 30000 }, async () => {
     const sn = new SupernoteX(await readFileToUint8Array("nomad-3.15.27-blank-2p.note"))