diff --git a/src/net/http/httputil/reverseproxy.go b/src/net/http/httputil/reverseproxy.go
index ab46370..5a0c1ed 100644
--- a/src/net/http/httputil/reverseproxy.go
+++ b/src/net/http/httputil/reverseproxy.go
@@ -100,6 +100,24 @@
 	"Upgrade",
 }
 
+type requestCanceler interface {
+	CancelRequest(*http.Request)
+}
+
+type runOnFirstRead struct {
+	io.Reader
+
+	fn func() // Run before first Read, then set to nil
+}
+
+func (c *runOnFirstRead) Read(bs []byte) (int, error) {
+	if c.fn != nil {
+		c.fn()
+		c.fn = nil
+	}
+	return c.Reader.Read(bs)
+}
+
 func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	transport := p.Transport
 	if transport == nil {
@@ -109,6 +127,34 @@
 	outreq := new(http.Request)
 	*outreq = *req // includes shallow copies of maps, but okay
 
+	if closeNotifier, ok := rw.(http.CloseNotifier); ok {
+		if requestCanceler, ok := transport.(requestCanceler); ok {
+			reqDone := make(chan struct{})
+			defer close(reqDone)
+
+			clientGone := closeNotifier.CloseNotify()
+
+			outreq.Body = struct {
+				io.Reader
+				io.Closer
+			}{
+				Reader: &runOnFirstRead{
+					Reader: outreq.Body,
+					fn: func() {
+						go func() {
+							select {
+							case <-clientGone:
+								requestCanceler.CancelRequest(outreq)
+							case <-reqDone:
+							}
+						}()
+					},
+				},
+				Closer: outreq.Body,
+			}
+		}
+	}
+
 	p.Director(outreq)
 	outreq.Proto = "HTTP/1.1"
 	outreq.ProtoMajor = 1
diff --git a/src/net/http/httputil/reverseproxy_test.go b/src/net/http/httputil/reverseproxy_test.go
index e9539b4..539c5e8 100644
--- a/src/net/http/httputil/reverseproxy_test.go
+++ b/src/net/http/httputil/reverseproxy_test.go
@@ -8,6 +8,7 @@
 
 import (
 	"io/ioutil"
+	"log"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -211,3 +212,58 @@
 		t.Error("maxLatencyWriter flushLoop() never exited")
 	}
 }
+
+func TestReverseProxyCancellation(t *testing.T) {
+	const backendResponse = "I am the backend"
+
+	reqInFlight := make(chan struct{})
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		close(reqInFlight)
+
+		select {
+		case <-time.After(10 * time.Second):
+			// Note: this should only happen in broken implementations, and the
+			// closenotify case should be instantaneous.
+			t.Log("Failed to close backend connection")
+			t.Fail()
+		case <-w.(http.CloseNotifier).CloseNotify():
+		}
+
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(backendResponse))
+	}))
+
+	defer backend.Close()
+
+	backend.Config.ErrorLog = log.New(ioutil.Discard, "", 0)
+
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+
+	// Discards errors of the form:
+	// http: proxy error: read tcp 127.0.0.1:44643: use of closed network connection
+	proxyHandler.ErrorLog = log.New(ioutil.Discard, "", 0)
+
+	frontend := httptest.NewServer(proxyHandler)
+	defer frontend.Close()
+
+	getReq, _ := http.NewRequest("GET", frontend.URL, nil)
+	go func() {
+		<-reqInFlight
+		http.DefaultTransport.(*http.Transport).CancelRequest(getReq)
+	}()
+	res, err := http.DefaultClient.Do(getReq)
+	if res != nil {
+		t.Fatal("Non-nil response")
+	}
+	if err == nil {
+		// This should be an error like:
+		// Get http://127.0.0.1:58079: read tcp 127.0.0.1:58079:
+		//    use of closed network connection
+		t.Fatal("DefaultClient.Do() returned nil error")
+	}
+}