diff --git a/src/net/http/request.go b/src/net/http/request.go
index 997169ce69..194b867c8c 100644
--- a/src/net/http/request.go
+++ b/src/net/http/request.go
@@ -911,6 +911,11 @@ func putTextprotoReader(r *textproto.Reader) {
 }
 
 // ReadRequest reads and parses an incoming request from b.
+//
+// ReadRequest is a low-level function and should only be used for
+// specialized applications; most code should use the Server to read
+// requests and handle them via the Handler interface. ReadRequest
+// only supports HTTP/1.x requests. For HTTP/2, use golang.org/x/net/http2.
 func ReadRequest(b *bufio.Reader) (*Request, error) {
 	return readRequest(b, deleteHostHeader)
 }