diff --git a/src/net/http/server.go b/src/net/http/server.go
index f554c81300..feff20045a 100644
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -2488,7 +2488,12 @@ func ServeTLS(l net.Listener, handler Handler, certFile, keyFile string) error {
 // A Server defines parameters for running an HTTP server.
 // The zero value for Server is a valid configuration.
 type Server struct {
-	Addr    string  // TCP address to listen on, ":http" if empty
+	// Addr optionally specifies the TCP address for the server to listen on,
+	// in the form "host:port". If empty, ":http" (port 80) is used.
+	// The service names are defined in RFC 6335 and assigned by IANA.
+	// See net.Dial for details of the address format.
+	Addr string
+
 	Handler Handler // handler to invoke, http.DefaultServeMux if nil
 
 	// TLSConfig optionally provides a TLS configuration for use