diff --git a/guix-data-service/web/server.scm b/guix-data-service/web/server.scm
index 3044e4d..20b34cb 100644
--- a/guix-data-service/web/server.scm
+++ b/guix-data-service/web/server.scm
@@ -75,10 +75,6 @@
                (request-method request)
                (uri-path (request-uri request)))))
     #:unwind? #t)
-  ;; The fibers web server uses a 1024 byte buffer, so increase this
-  (setvbuf (request-port request)
-           'block
-           (expt 2 16))
   (apply values
          (let-values (((request-components mime-types)
                        (request->path-components-and-mime-type request)))
@@ -294,6 +290,7 @@ port. Also, the port used can be changed by passing the --port option.\n"
                                                       exn
                                                       #f))
                                           #:code 500))))))
+                     #:connection-buffer-size (expt 2 16)
                      #:host host
                      #:port port)))
                 #:unwind? #t)))