diff --git a/scheme/httpd/response.scm b/scheme/httpd/response.scm
index 74bc184..706d6c8 100644
--- a/scheme/httpd/response.scm
+++ b/scheme/httpd/response.scm
@@ -187,7 +187,8 @@ misconfiguration and was unable to complete your request.
 <P>
 Please inform the server administrator, ~A, of the circumstances leading to
 the error, and time it occured.~%"
-		 (httpd-options-server-admin options))
+		 (or (httpd-options-server-admin options)
+		     "[no mail address available]"))
 	 (send-message port)
 	 (close-html port))))