diff --git a/lib/engines/puppeteer.js b/lib/engines/puppeteer.js
index c74ae1b..496f355 100644
--- a/lib/engines/puppeteer.js
+++ b/lib/engines/puppeteer.js
@@ -41,7 +41,7 @@ class Puppeteer extends engine.Engine {
 
     async render(req, res, next) {
         const url = req.query.url || "https://www.google.com/";
-        const format = req.query.format || "PNG";
+        const format = (req.query.format || "PNG").toLowerCase();
         const pageFormat = req.query.page_format || "A4";
         const waitUntil = req.query.wait_until || "load";
         const printBackground = req.query.print_background !== "0";
@@ -56,7 +56,7 @@ class Puppeteer extends engine.Engine {
         const scaleFactor = parseInt(req.query.scale_factor || 1);
         const timeout = parseInt(req.query.timeout || 500);
         const cookie = req.query.cookie || [];
-        const isPdf = ["pdf"].indexOf(format.toLowerCase()) !== -1;
+        const isPdf = ["pdf"].indexOf(format) !== -1;
         const cookieA = Array.isArray(cookie) ? cookie : [cookie];
 
         // builds a new page instance (in a safe manner), taking
@@ -141,14 +141,16 @@ class Puppeteer extends engine.Engine {
                 res.send(data);
             } else {
                 let data = await page.screenshot({
-                    fullPage: fullPage
+                    fullPage: fullPage,
+                    type: format
                 });
                 if (trim) {
                     const image = await jimp.read(data);
+                    const mime = "image/" + format;
                     image.autocrop();
-                    data = await image.getBufferAsync("image/png");
+                    data = await image.getBufferAsync(mime);
                 }
-                res.type("png");
+                res.type(format);
                 res.send(data);
             }
         } finally {
diff --git a/test/engines/puppeteer.js b/test/engines/puppeteer.js
index 1ca7948..7a84463 100644
--- a/test/engines/puppeteer.js
+++ b/test/engines/puppeteer.js
@@ -42,6 +42,34 @@ describe("Puppeteer", function() {
         }
     });
 
+    it("should render a jpeg", async () => {
+        const engine = new puppeteer.Puppeteer();
+        await engine.init();
+
+        try {
+            const req = {
+                query: {
+                    url: "https://example.com/",
+                    format: "jpeg"
+                },
+                body: {}
+            };
+            const res = {
+                send: function(data) {
+                    this.data = data;
+                },
+                type: function(file) {
+                    this.file = file;
+                }
+            };
+            await engine.render(req, res);
+            assert.ok(res.data);
+            assert.strictEqual(res.file, "jpeg");
+        } finally {
+            await engine.destroy();
+        }
+    });
+
     it("should open new page", async () => {
         const engine = new puppeteer.Puppeteer();
         await engine.init();