diff --git a/src/go.mod b/src/go.mod
index 386b51a6569f5a..1971741efa5fb4 100644
--- a/src/go.mod
+++ b/src/go.mod
@@ -4,7 +4,7 @@ go 1.17
 
 require (
 	golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e
-	golang.org/x/net v0.0.0-20211101194204-95aca89e93de
+	golang.org/x/net v0.0.0-20211201233630-85e122b1a9b3
 )
 
 require (
diff --git a/src/go.sum b/src/go.sum
index 1f328206ecb2bb..32c714d1edf172 100644
--- a/src/go.sum
+++ b/src/go.sum
@@ -1,8 +1,8 @@
 golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e h1:8foAy0aoO5GkqCvAEJ4VC4P3zksTg4X4aJCDpZzmgQI=
 golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20211101194204-95aca89e93de h1:dKoXPECQZ51dGVSkuiD9YzeNpLT4UPUY4d3xo0sWrkU=
-golang.org/x/net v0.0.0-20211101194204-95aca89e93de/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.0.0-20211201233630-85e122b1a9b3 h1:0tKANouoxlq5b2OS7rABX92sfG5Dkz24NFtLSu09W3o=
+golang.org/x/net v0.0.0-20211201233630-85e122b1a9b3/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744 h1:yhBbb4IRs2HS9PPlAg6DMC6mUOKexJBNsLf4Z+6En1Q=
diff --git a/src/net/http/h2_bundle.go b/src/net/http/h2_bundle.go
index 9112079a2246dc..7e1195cfd775eb 100644
--- a/src/net/http/h2_bundle.go
+++ b/src/net/http/h2_bundle.go
@@ -7658,36 +7658,49 @@ func (cc *http2ClientConn) RoundTrip(req *Request) (*Response, error) {
 		}
 	}
 
+	handleResponseHeaders := func() (*Response, error) {
+		res := cs.res
+		if res.StatusCode > 299 {
+			// On error or status code 3xx, 4xx, 5xx, etc abort any
+			// ongoing write, assuming that the server doesn't care
+			// about our request body. If the server replied with 1xx or
+			// 2xx, however, then assume the server DOES potentially
+			// want our body (e.g. full-duplex streaming:
+			// golang.org/issue/13444). If it turns out the server
+			// doesn't, they'll RST_STREAM us soon enough. This is a
+			// heuristic to avoid adding knobs to Transport. Hopefully
+			// we can keep it.
+			cs.abortRequestBodyWrite()
+		}
+		res.Request = req
+		res.TLS = cc.tlsState
+		if res.Body == http2noBody && http2actualContentLength(req) == 0 {
+			// If there isn't a request or response body still being
+			// written, then wait for the stream to be closed before
+			// RoundTrip returns.
+			if err := waitDone(); err != nil {
+				return nil, err
+			}
+		}
+		return res, nil
+	}
+
 	for {
 		select {
 		case <-cs.respHeaderRecv:
-			res := cs.res
-			if res.StatusCode > 299 {
-				// On error or status code 3xx, 4xx, 5xx, etc abort any
-				// ongoing write, assuming that the server doesn't care
-				// about our request body. If the server replied with 1xx or
-				// 2xx, however, then assume the server DOES potentially
-				// want our body (e.g. full-duplex streaming:
-				// golang.org/issue/13444). If it turns out the server
-				// doesn't, they'll RST_STREAM us soon enough. This is a
-				// heuristic to avoid adding knobs to Transport. Hopefully
-				// we can keep it.
-				cs.abortRequestBodyWrite()
-			}
-			res.Request = req
-			res.TLS = cc.tlsState
-			if res.Body == http2noBody && http2actualContentLength(req) == 0 {
-				// If there isn't a request or response body still being
-				// written, then wait for the stream to be closed before
-				// RoundTrip returns.
-				if err := waitDone(); err != nil {
-					return nil, err
-				}
-			}
-			return res, nil
+			return handleResponseHeaders()
 		case <-cs.abort:
-			waitDone()
-			return nil, cs.abortErr
+			select {
+			case <-cs.respHeaderRecv:
+				// If both cs.respHeaderRecv and cs.abort are signaling,
+				// pick respHeaderRecv. The server probably wrote the
+				// response and immediately reset the stream.
+				// golang.org/issue/49645
+				return handleResponseHeaders()
+			default:
+				waitDone()
+				return nil, cs.abortErr
+			}
 		case <-ctx.Done():
 			err := ctx.Err()
 			cs.abortStream(err)
@@ -7747,6 +7760,9 @@ func (cs *http2clientStream) writeRequest(req *Request) (err error) {
 		return err
 	}
 	cc.addStreamLocked(cs) // assigns stream ID
+	if http2isConnectionCloseRequest(req) {
+		cc.doNotReuse = true
+	}
 	cc.mu.Unlock()
 
 	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
@@ -7770,12 +7786,12 @@ func (cs *http2clientStream) writeRequest(req *Request) (err error) {
 	}
 
 	continueTimeout := cc.t.expectContinueTimeout()
-	if continueTimeout != 0 &&
-		!httpguts.HeaderValuesContainsToken(
-			req.Header["Expect"],
-			"100-continue") {
-		continueTimeout = 0
-		cs.on100 = make(chan struct{}, 1)
+	if continueTimeout != 0 {
+		if !httpguts.HeaderValuesContainsToken(req.Header["Expect"], "100-continue") {
+			continueTimeout = 0
+		} else {
+			cs.on100 = make(chan struct{}, 1)
+		}
 	}
 
 	// Past this point (where we send request headers), it is possible for
@@ -7844,6 +7860,7 @@ func (cs *http2clientStream) writeRequest(req *Request) (err error) {
 		case <-respHeaderTimer:
 			return http2errTimeout
 		case <-respHeaderRecv:
+			respHeaderRecv = nil
 			respHeaderTimer = nil // keep waiting for END_STREAM
 		case <-cs.abort:
 			return cs.abortErr
diff --git a/src/vendor/modules.txt b/src/vendor/modules.txt
index f61fc51ba82e25..0981b7f333f873 100644
--- a/src/vendor/modules.txt
+++ b/src/vendor/modules.txt
@@ -8,7 +8,7 @@ golang.org/x/crypto/curve25519
 golang.org/x/crypto/hkdf
 golang.org/x/crypto/internal/subtle
 golang.org/x/crypto/poly1305
-# golang.org/x/net v0.0.0-20211101194204-95aca89e93de
+# golang.org/x/net v0.0.0-20211201233630-85e122b1a9b3
 ## explicit; go 1.17
 golang.org/x/net/dns/dnsmessage
 golang.org/x/net/http/httpguts