diff --git a/src/IsoFS.ts b/src/IsoFS.ts
index 15b9f25..4f29eda 100644
--- a/src/IsoFS.ts
+++ b/src/IsoFS.ts
@@ -208,7 +208,7 @@ export const Iso: Backend = {
 			description: 'The ISO file in a buffer',
 			validator(arg: unknown) {
 				if (!(arg instanceof ArrayBuffer)) {
-					throw new TypeError();
+					throw new TypeError('data is not an ArrayBuffer');
 				}
 			},
 		},