diff --git a/lib/chibi/mime.scm b/lib/chibi/mime.scm
index 8d112935..882dea93 100644
--- a/lib/chibi/mime.scm
+++ b/lib/chibi/mime.scm
@@ -208,6 +208,15 @@
               (lp (+ i 2) from res)))
           (lp (+ i 1) from res))))))
 
+;;> Write out an alist of headers in mime format.
+
+(define (mime-write-headers headers out)
+  (for-each
+   (lambda (h)
+     (display (car h) out) (display ": " out)
+     (display (cdr h) out) (display "\r\n" out))
+   headers))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; message parsing
 
diff --git a/lib/chibi/mime.sld b/lib/chibi/mime.sld
index c2c6682c..f9b37b39 100644
--- a/lib/chibi/mime.sld
+++ b/lib/chibi/mime.sld
@@ -2,7 +2,7 @@
 (define-library (chibi mime)
   (export assq-ref mime-header-fold mime-headers->list
           mime-parse-content-type mime-decode-header
-          mime-message-fold mime-message->sxml)
+          mime-message-fold mime-message->sxml mime-write-headers)
   (import (chibi) (chibi base64) (chibi quoted-printable)
           (chibi string) (chibi io))
   (include "mime.scm"))