diff --git a/test/cache.js b/test/cache.js
index 65cc5a8..e531b56 100644
--- a/test/cache.js
+++ b/test/cache.js
@@ -50,6 +50,7 @@ test('Binary responses are cached', async t => {
 	const firstResponse = await got(s.url + endpoint, {cache, encoding});
 	const secondResponse = await got(s.url + endpoint, {cache, encoding});
 
+	t.true(firstResponse.body instanceof Buffer);
 	t.is(firstResponse.body.toString(), secondResponse.body.toString());
 });