diff --git a/http2/transport.go b/http2/transport.go
index 040d9327c..2cd3c6ec7 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -1301,6 +1301,26 @@ func (cc *ClientConn) roundTrip(req *http.Request, streamf func(*clientStream))
 		donec:                make(chan struct{}),
 	}
 
+	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
+	if !cc.t.disableCompression() &&
+		req.Header.Get("Accept-Encoding") == "" &&
+		req.Header.Get("Range") == "" &&
+		!cs.isHead {
+		// Request gzip only, not deflate. Deflate is ambiguous and
+		// not as universally supported anyway.
+		// See: https://zlib.net/zlib_faq.html#faq39
+		//
+		// Note that we don't request this for HEAD requests,
+		// due to a bug in nginx:
+		//   http://trac.nginx.org/nginx/ticket/358
+		//   https://golang.org/issue/5522
+		//
+		// We don't request gzip if the request is for a range, since
+		// auto-decoding a portion of a gzipped document will just fail
+		// anyway. See https://golang.org/issue/8923
+		cs.requestedGzip = true
+	}
+
 	go cs.doRequest(req, streamf)
 
 	waitDone := func() error {
@@ -1449,26 +1469,6 @@ func (cs *clientStream) writeRequest(req *http.Request, streamf func(*clientStre
 		streamf(cs)
 	}
 
-	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
-	if !cc.t.disableCompression() &&
-		req.Header.Get("Accept-Encoding") == "" &&
-		req.Header.Get("Range") == "" &&
-		!cs.isHead {
-		// Request gzip only, not deflate. Deflate is ambiguous and
-		// not as universally supported anyway.
-		// See: https://zlib.net/zlib_faq.html#faq39
-		//
-		// Note that we don't request this for HEAD requests,
-		// due to a bug in nginx:
-		//   http://trac.nginx.org/nginx/ticket/358
-		//   https://golang.org/issue/5522
-		//
-		// We don't request gzip if the request is for a range, since
-		// auto-decoding a portion of a gzipped document will just fail
-		// anyway. See https://golang.org/issue/8923
-		cs.requestedGzip = true
-	}
-
 	continueTimeout := cc.t.expectContinueTimeout()
 	if continueTimeout != 0 {
 		if !httpguts.HeaderValuesContainsToken(req.Header["Expect"], "100-continue") {
diff --git a/http2/transport_test.go b/http2/transport_test.go
index d875338a2..2171359ca 100644
--- a/http2/transport_test.go
+++ b/http2/transport_test.go
@@ -2895,6 +2895,7 @@ func TestRoundTripDoesntConsumeRequestBodyEarly(t *testing.T) {
 	cc := &ClientConn{
 		closed:      true,
 		reqHeaderMu: make(chan struct{}, 1),
+		t:           &Transport{},
 	}
 	_, err := cc.RoundTrip(req)
 	if err != errClientConnUnusable {