diff --git a/compy_test.go b/compy_test.go
new file mode 100644
index 0000000..59dbb6f
--- /dev/null
+++ b/compy_test.go
@@ -0,0 +1,86 @@
+package main
+
+import (
+	. "gopkg.in/check.v1"
+
+	jpegp "image/jpeg"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/ahmetalpbalkan/go-httpbin"
+	"github.com/barnacs/compy/proxy"
+	tc "github.com/barnacs/compy/transcoder"
+	"github.com/chai2010/webp"
+)
+
+func Test(t *testing.T) {
+	TestingT(t)
+}
+
+type CompyTest struct {
+	client *http.Client
+	server *httptest.Server
+	proxy  *proxy.Proxy
+}
+
+var _ = Suite(&CompyTest{})
+
+func (s *CompyTest) SetUpSuite(c *C) {
+	s.server = httptest.NewServer(httpbin.GetMux())
+
+	s.proxy = proxy.New()
+	s.proxy.AddTranscoder("image/jpeg", tc.NewJpeg(50))
+	s.proxy.AddTranscoder("text/html", &tc.Gzip{&tc.Identity{}, *gzip, true})
+	go func() {
+		err := s.proxy.Start(*host)
+		if err != nil {
+			c.Fatal(err)
+		}
+	}()
+
+	proxyUrl := &url.URL{Scheme: "http", Host: "localhost" + *host}
+	s.client = &http.Client{Transport: &http.Transport{Proxy: http.ProxyURL(proxyUrl)}}
+}
+
+func (s *CompyTest) TearDownSuite(c *C) {
+	s.server.Close()
+
+	// TODO: Go 1.8 will provide http.Server.Shutdown for proxy.Proxy
+}
+
+func (s *CompyTest) TestHttpBin(c *C) {
+	resp, err := s.client.Get(s.server.URL + "/status/200")
+	c.Assert(err, IsNil)
+	c.Assert(resp.StatusCode, Equals, 200)
+}
+
+func (s *CompyTest) TestJpeg(c *C) {
+	req, err := http.NewRequest("GET", s.server.URL+"/image/jpeg", nil)
+	c.Assert(err, IsNil)
+
+	resp, err := s.client.Do(req)
+	c.Assert(err, IsNil)
+	defer resp.Body.Close()
+	c.Assert(resp.StatusCode, Equals, 200)
+	c.Assert(resp.Header.Get("Content-Type"), Equals, "image/jpeg")
+
+	_, err = jpegp.Decode(resp.Body)
+	c.Assert(err, IsNil)
+}
+
+func (s *CompyTest) TestWebP(c *C) {
+	req, err := http.NewRequest("GET", s.server.URL+"/image/jpeg", nil)
+	c.Assert(err, IsNil)
+	req.Header.Add("Accept", "image/webp,image/jpeg")
+
+	resp, err := s.client.Do(req)
+	c.Assert(err, IsNil)
+	defer resp.Body.Close()
+	c.Assert(resp.StatusCode, Equals, 200)
+	c.Assert(resp.Header.Get("Content-Type"), Equals, "image/webp")
+
+	_, err = webp.Decode(resp.Body)
+	c.Assert(err, IsNil)
+}
diff --git a/transcoder/jpeg.go b/transcoder/jpeg.go
index 6dafe28..4c5e371 100644
--- a/transcoder/jpeg.go
+++ b/transcoder/jpeg.go
@@ -29,6 +29,7 @@ func (t *Jpeg) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, heade
 	}
 
 	if SupportsWebP(headers) {
+		w.Header().Set("Content-Type", "image/webp")
 		options := webp.Options{
 			Lossless: false,
 			Quality:  float32(t.encOptions.Quality),