diff --git a/collects/tests/web-server/http/xexpr.rkt b/collects/tests/web-server/http/xexpr.rkt
new file mode 100644
index 0000000000..31b132202e
--- /dev/null
+++ b/collects/tests/web-server/http/xexpr.rkt
@@ -0,0 +1,56 @@
+#lang racket
+(require tests/eli-tester
+         web-server/private/timer
+         web-server/private/connection-manager
+         web-server/http/response
+         web-server/http
+         "../util.rkt")
+
+(define (write-response r [redact? #t])
+  (define-values (i-port o-port) (make-pipe))
+  (define conn
+    (connection 0 (start-timer +inf.0 void)
+                i-port o-port (current-custodian) #t))
+  (output-response conn r)
+  (close-output-port o-port)
+  (define bs (port->bytes i-port))
+  (if redact? (redact bs) bs))
+
+(test
+ (write-response (make-xexpr-response '(a ([href "#"]) "link")))
+ =>
+ #"HTTP/1.1 200 Okay\r\nDate: REDACTED GMT\r\nLast-Modified: REDACTED GMT\r\nServer: Racket\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\nContent-Length: 20\r\n\r\n<a href=\"#\">link</a>"
+ 
+ (write-response (make-xexpr-response '(a ([href "#"]) "link")
+                                      #:code 404))
+ =>
+ #"HTTP/1.1 404 Okay\r\nDate: REDACTED GMT\r\nLast-Modified: REDACTED GMT\r\nServer: Racket\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\nContent-Length: 20\r\n\r\n<a href=\"#\">link</a>"
+ 
+ (write-response (make-xexpr-response '(a ([href "#"]) "link")
+                                      #:message #"Bad request"))
+ =>
+ #"HTTP/1.1 200 Bad request\r\nDate: REDACTED GMT\r\nLast-Modified: REDACTED GMT\r\nServer: Racket\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\nContent-Length: 20\r\n\r\n<a href=\"#\">link</a>"
+ 
+ (regexp-replace 
+  #"Date: [a-zA-Z0-9:, ]+ GMT\r\n"
+  (write-response (make-xexpr-response '(a ([href "#"]) "link")
+                                       #:seconds 0)
+                  #f)
+  #"Date: REDACTED GMT\r\n")
+ =>
+ #"HTTP/1.1 200 Okay\r\nDate: REDACTED GMT\r\nLast-Modified: Thu, 01 Jan 1970 00:00:00 GMT\r\nServer: Racket\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\nContent-Length: 20\r\n\r\n<a href=\"#\">link</a>"
+ 
+ (write-response (make-xexpr-response '(a ([href "#"]) "link")
+                                      #:mime-type #"application/xml"))
+ =>
+ #"HTTP/1.1 200 Okay\r\nDate: REDACTED GMT\r\nLast-Modified: REDACTED GMT\r\nServer: Racket\r\nContent-Type: application/xml\r\nConnection: close\r\nContent-Length: 20\r\n\r\n<a href=\"#\">link</a>"
+ 
+ (write-response (make-xexpr-response '(a ([href "#"]) "link")
+                                      #:headers (list (header #"head" #"value"))))
+ =>
+ #"HTTP/1.1 200 Okay\r\nDate: REDACTED GMT\r\nLast-Modified: REDACTED GMT\r\nServer: Racket\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\nContent-Length: 20\r\nhead: value\r\n\r\n<a href=\"#\">link</a>"
+ 
+ (write-response (make-xexpr-response '(a ([href "#"]) "link")
+                                      #:preamble #"<<!something XMLy>>"))
+ =>
+ #"HTTP/1.1 200 Okay\r\nDate: REDACTED GMT\r\nLast-Modified: REDACTED GMT\r\nServer: Racket\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\nContent-Length: 39\r\n\r\n<<!something XMLy>><a href=\"#\">link</a>")
\ No newline at end of file
diff --git a/collects/web-server/http/response-structs.rkt b/collects/web-server/http/response-structs.rkt
index c6fb464fc4..3f9da98183 100644
--- a/collects/web-server/http/response-structs.rkt
+++ b/collects/web-server/http/response-structs.rkt
@@ -77,10 +77,11 @@
          #:message [message #"Okay"]
          #:seconds [seconds (current-seconds)]
          #:mime-type [mime-type TEXT/HTML-MIME-TYPE]
-         #:headers [hdrs empty])
+         #:headers [hdrs empty]
+         #:preamble [preamble #""])
   (make-response/full 
    code message seconds mime-type hdrs
-   (list (string->bytes/utf-8 (xexpr->string xexpr)))))
+   (list preamble (string->bytes/utf-8 (xexpr->string xexpr)))))
 
 (provide/contract
  [struct response/basic
@@ -106,7 +107,7 @@
  [response/c contract?]
  [make-xexpr-response 
   ((pretty-xexpr/c)
-   (#:code number? #:message bytes? #:seconds number? #:mime-type bytes? #:headers (listof header?))
+   (#:code number? #:message bytes? #:seconds number? #:mime-type bytes? #:headers (listof header?) #:preamble bytes?)
    . ->* . response/full?)]
  [normalize-response ((response/c) (boolean?) . ->* . (or/c response/full? response/incremental?))]
  [TEXT/HTML-MIME-TYPE bytes?])
diff --git a/collects/web-server/scribblings/http.scrbl b/collects/web-server/scribblings/http.scrbl
index 2de2af8a3a..45cf2fbc1b 100644
--- a/collects/web-server/scribblings/http.scrbl
+++ b/collects/web-server/scribblings/http.scrbl
@@ -237,13 +237,14 @@ Here is an example typical of what you will find in many applications:
                               [#:message message bytes? #"Okay"]
                               [#:seconds seconds number? (current-seconds)]
                               [#:mime-type mime-type bytes? TEXT/HTML-MIME-TYPE]
-                              [#:headers headers (listof header?) empty])
+                              [#:headers headers (listof header?) empty]
+                              [#:preamble preamble bytes? #""])
          response/full?]{
  Equivalent to
  @racketblock[
  (make-response/full 
   code message seconds mime-type headers
-  (list (string->bytes/utf-8 (xexpr->string xexpr))))
+  (list preamble (string->bytes/utf-8 (xexpr->string xexpr))))
  ]}
                          
 @defproc[(normalize-response [response response/c] [close? boolean? #f])