diff --git a/collects/racket/date.rkt b/collects/racket/date.rkt
index c37deeabdd..49f7e79a11 100644
--- a/collects/racket/date.rkt
+++ b/collects/racket/date.rkt
@@ -131,7 +131,7 @@
       [(iso-8601)
        (values
         (list year "-" (add-zero (date-month date)) "-" (add-zero (date-day date)))
-        (list " " hour24 ":" minute ":" second))]
+        (list "T" hour24 ":" minute ":" second))]
       [(rfc2822)
        (values
         (list (substring week-day 0 3) ", " day " " (substring month 0 3) " " year)
diff --git a/collects/tests/racket/date.rktl b/collects/tests/racket/date.rktl
index e52a8565d6..af8c5cb3c9 100644
--- a/collects/tests/racket/date.rktl
+++ b/collects/tests/racket/date.rktl
@@ -56,7 +56,7 @@
   (test-string 'irish #f "Thursday, 4th May 2006")
   (test-string 'irish #t "Thursday, 4th May 2006, 3:02am")
   (test-string 'iso-8601 #f "2006-05-04")
-  (test-string 'iso-8601 #t "2006-05-04 03:02:01")
+  (test-string 'iso-8601 #t "2006-05-04T03:02:01")
   (test-string 'rfc2822 #f "Thu, 4 May 2006")
   (test-string 'rfc2822 #t "Thu, 4 May 2006 03:02:01 -0600")
   (test-string 'julian #f "JD 2 453 860")
diff --git a/doc/release-notes/racket/HISTORY.txt b/doc/release-notes/racket/HISTORY.txt
index 90e2b7b783..0aefd14db2 100644
--- a/doc/release-notes/racket/HISTORY.txt
+++ b/doc/release-notes/racket/HISTORY.txt
@@ -7,6 +7,7 @@ racket/serialize: fxvectors and flvectors are serializable
 racket/net: added uri-path-segment-unreserved-encode
 racket/url: added current-url-encode-mode
 ffi/com: added com-get-property*
+racket/date: fixed 'iso-8601 date formatting
 
 Version 5.3.1.8
 file/untar: added