I just noticed that if empty string "" is passed into `(redirect-to)`, the response will not include a Location header (even though the header object exists in the response object generated by `(redirect-to)`. While passing in empty string is a client bug, perhaps it's better to simply stop the input in the first place? If so - below is a plausible patch for web-server/http/redirect.ss Thanks, yc --- /usr/local/plt/lib/plt/collects/web-server/http/redirect.ss 2008-11-16 11:34:46.000000000 -0800 +++ plt-scheme/web-server/http/redirect.ss 2009-03-03 23:00:10.000000000 -0800 @@ -24,7 +24,8 @@ (provide/contract [redirect-to - (->* (string?) (redirection-status? #:headers (listof header?)) + (->* ((and/c string? (lambda (s) (> (string-length s) 0)))) + (redirection-status? #:headers (listof header?)) response/full?)] [redirection-status? (any/c . -> . boolean?)] [permanently redirection-status?]