diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index c3d4a95c03..59bffd0ae8 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -83,6 +83,13 @@ const DefaultMaxIdleConnsPerHost = 2
 // being written while the response body is streamed. Go's HTTP/2
 // implementation does support full duplex, but many CONNECT proxies speak
 // HTTP/1.x.
+//
+// Responses with status codes in the 1xx range are either handled
+// automatically (100 expect-continue) or ignored. The one
+// exception is HTTP status code 101 (Switching Protocols), which is
+// considered a terminal status and returned by RoundTrip. To see the
+// ignored 1xx responses, use the httptrace trace package's
+// ClientTrace.Got1xxResponse.
 type Transport struct {
 	idleMu     sync.Mutex
 	wantIdle   bool                                // user has requested to close all idle conns
@@ -1674,7 +1681,10 @@ func (pc *persistConn) readResponse(rc requestAndChan, trace *httptrace.ClientTr
 				continueCh = nil
 			}
 		}
-		if 100 <= resCode && resCode <= 199 {
+		is1xx := 100 <= resCode && resCode <= 199
+		// treat 101 as a terminal status, see issue 26161
+		is1xxNonTerminal := is1xx && resCode != StatusSwitchingProtocols
+		if is1xxNonTerminal {
 			num1xx++
 			if num1xx > max1xxResponses {
 				return nil, errors.New("net/http: too many 1xx informational responses")
diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index 979b8a9009..87361e81ca 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -2375,6 +2375,29 @@ func TestTransportLimits1xxResponses(t *testing.T) {
 	}
 }
 
+// Issue 26161: the HTTP client must treat 101 responses
+// as the final response.
+func TestTransportTreat101Terminal(t *testing.T) {
+	setParallel(t)
+	defer afterTest(t)
+	cst := newClientServerTest(t, h1Mode, HandlerFunc(func(w ResponseWriter, r *Request) {
+		conn, buf, _ := w.(Hijacker).Hijack()
+		buf.Write([]byte("HTTP/1.1 101 Switching Protocols\r\n\r\n"))
+		buf.Write([]byte("HTTP/1.1 204 No Content\r\n\r\n"))
+		buf.Flush()
+		conn.Close()
+	}))
+	defer cst.close()
+	res, err := cst.c.Get(cst.ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer res.Body.Close()
+	if res.StatusCode != StatusSwitchingProtocols {
+		t.Errorf("StatusCode = %v; want 101 Switching Protocols", res.StatusCode)
+	}
+}
+
 type proxyFromEnvTest struct {
 	req string // URL to fetch; blank means "http://example.com"