diff --git a/http2/transport.go b/http2/transport.go
index e6aede6..653a1a0 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -2637,19 +2637,24 @@
 		}
 		cc.mu.Unlock()
 	}
-	cc.wmu.Lock()
-	if err := cc.fr.WritePing(false, p); err != nil {
-		cc.wmu.Unlock()
-		return err
-	}
-	if err := cc.bw.Flush(); err != nil {
-		cc.wmu.Unlock()
-		return err
-	}
-	cc.wmu.Unlock()
+	errc := make(chan error, 1)
+	go func() {
+		cc.wmu.Lock()
+		defer cc.wmu.Unlock()
+		if err := cc.fr.WritePing(false, p); err != nil {
+			errc <- err
+			return
+		}
+		if err := cc.bw.Flush(); err != nil {
+			errc <- err
+			return
+		}
+	}()
 	select {
 	case <-c:
 		return nil
+	case err := <-errc:
+		return err
 	case <-ctx.Done():
 		return ctx.Err()
 	case <-cc.readerDone:
diff --git a/http2/transport_test.go b/http2/transport_test.go
index 234a2f8..3c02695 100644
--- a/http2/transport_test.go
+++ b/http2/transport_test.go
@@ -3494,6 +3494,36 @@
 	ct.run()
 }
 
+func TestTransportPingWriteBlocks(t *testing.T) {
+	st := newServerTester(t,
+		func(w http.ResponseWriter, r *http.Request) {},
+		optOnlyServer,
+	)
+	defer st.Close()
+	tr := &Transport{
+		TLSClientConfig: tlsConfigInsecure,
+		DialTLS: func(network, addr string, cfg *tls.Config) (net.Conn, error) {
+			s, c := net.Pipe() // unbuffered, unlike a TCP conn
+			go func() {
+				// Read initial handshake frames.
+				// Without this, we block indefinitely in newClientConn,
+				// and never get to the point of sending a PING.
+				var buf [1024]byte
+				s.Read(buf[:])
+			}()
+			return c, nil
+		},
+		PingTimeout:     1 * time.Millisecond,
+		ReadIdleTimeout: 1 * time.Millisecond,
+	}
+	defer tr.CloseIdleConnections()
+	c := &http.Client{Transport: tr}
+	_, err := c.Get(st.ts.URL)
+	if err == nil {
+		t.Fatalf("Get = nil, want error")
+	}
+}
+
 func TestTransportPingWhenReading(t *testing.T) {
 	testCases := []struct {
 		name              string