I am in the progress of migrating an old banner system to a new one and in doing so I want to rewrite the old banner system's URL's to the new one. I load my banners via an AJAX request, and therefore I require the Access-Control-Allow-Origin to be set to *. I have the following VirtualHost configuration: <VirtualHost *:80> ServerAdmin [email protected] ServerName banner.studenten.net # we want to allow XMLHTTPRequests Header set Access-Control-Allow-Origin "*" RewriteEngine on RewriteMap bannersOldToNew txt:/home/user/banner.studenten.net/banner-studenten-net-to-ads-all4students-nl-map # check whether a zoneid exists in the query string RewriteCond %{QUERY_STRING} ^(.*)zoneid=([1-9][0-9]*)(.*) # make sure the requested banner has been mapped RewriteCond ${bannersOldToNew:%2|NOTFOUND} !=NOTFOUND # rewrite to ads.all4students.nl RewriteRule ^/ads/.* http://ads.all4students.nl/delivery/ajs.php?%1zoneid=${bannersOldToNew:%2}%3 [R] # else 404 or something ErrorLog ${APACHE_LOG_DIR}/banner.studenten.net-error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/banner.studenten.net-access.log combined </VirtualHost> My map file, /home/user/banner.studenten.net/banner-studenten-net-to-ads-all4students-nl-map, contains something like: # oldId newId 140 11 141 12 142 13 Based on the above configuration I was expecting the following: GET /ads/ajs.php?zoneid=140 HTTP/1.1 Host: banner.studenten.net HTTP/1.1 302 Found ... Access-Control-Allow-Origin: * Location: http://ads.all4students.nl/delivery/ajs.php?zoneid=11 But instead I get the following: GET /ads/ajs.php?zoneid=140 HTTP/1.1 Host: banner.studenten.net HTTP/1.1 302 Found ... Location: http://ads.all4students.nl/delivery/ajs.php?zoneid=11 Note the missing Access-Control-Allow-Origin header, this means the XMLHttpRequest is denied and the banner is not displayed. Any suggestions on how to fix this in Apache?