diff --git a/http2/transport.go b/http2/transport.go
index 80cff2a..86dd4c8 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -2560,7 +2560,9 @@
 
 func (s bodyWriterState) cancel() {
 	if s.timer != nil {
-		s.timer.Stop()
+		if s.timer.Stop() {
+			s.resc <- nil
+		}
 	}
 }
 
diff --git a/http2/transport_test.go b/http2/transport_test.go
index d0d0542..c7826b3 100644
--- a/http2/transport_test.go
+++ b/http2/transport_test.go
@@ -4628,3 +4628,39 @@
 
 	wg.Wait()
 }
+
+// Issue 42498: A request with a body will never be sent if the stream is
+// reset prior to sending any data.
+func TestTransportServerResetStreamAtHeaders(t *testing.T) {
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusUnauthorized)
+		return
+	}, optOnlyServer)
+	defer st.Close()
+
+	tr := &http.Transport{
+		TLSClientConfig:       tlsConfigInsecure,
+		MaxConnsPerHost:       1,
+		ExpectContinueTimeout: 10 * time.Second,
+	}
+
+	err := ConfigureTransport(tr)
+	if err != nil {
+		t.Fatal(err)
+	}
+	client := &http.Client{
+		Transport: tr,
+	}
+
+	req, err := http.NewRequest("POST", st.ts.URL, errorReader{io.EOF})
+	if err != nil {
+		t.Fatalf("unexpect new request error: %v", err)
+	}
+	req.ContentLength = 0 // so transport is tempted to sniff it
+	req.Header.Set("Expect", "100-continue")
+	res, err := client.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	res.Body.Close()
+}