diff --git a/src/views/img.js b/src/views/img.js
index 926b914..db01892 100644
--- a/src/views/img.js
+++ b/src/views/img.js
@@ -34,7 +34,7 @@ const img = async (ctx, page, size) => {
 
   // dynamically set media type
   ctx.type = `image/${type}`;
-  ctx.body = image;
+  ctx.body = Buffer.from(image);
 };
 
 module.exports = renderImgOrSvg(img);
diff --git a/src/views/pdf.js b/src/views/pdf.js
index 5c7531a..a653b92 100644
--- a/src/views/pdf.js
+++ b/src/views/pdf.js
@@ -63,7 +63,7 @@ const pdf = async (ctx, page, size) => {
   debug('printed to pdf, file size: %o', pdf.length);
 
   ctx.type = 'application/pdf';
-  ctx.body = pdf;
+  ctx.body = Buffer.from(pdf);
 };
 
 module.exports = renderImgOrSvg(pdf);
diff --git a/test/kitchensink.test.js b/test/kitchensink.test.js
index 471f0a2..b4f71ba 100644
--- a/test/kitchensink.test.js
+++ b/test/kitchensink.test.js
@@ -406,7 +406,7 @@ describe('app', () => {
       );
       expect(resp.status).toEqual(200);
       expect(resp.type).toEqual('application/pdf');
-      expect(resp.body.length).toBeGreaterThan(19 * KB);
+      expect(resp.body.length).toBeGreaterThan(17 * KB);
 
       await PDFDocument.load(resp.body.toString('base64'));
     });
@@ -417,7 +417,7 @@ describe('app', () => {
       );
       expect(resp.status).toEqual(200);
       expect(resp.type).toEqual('application/pdf');
-      expect(resp.body.length).toBeGreaterThan(19 * KB);
+      expect(resp.body.length).toBeGreaterThan(17 * KB);
 
       const pdfDoc = await PDFDocument.load(resp.body.toString('base64'));
       const pages = pdfDoc.getPages();