I have an httpd server proxying the requests to 2 different tomcat servers. One of my server handles the authentication and returns a specific http error code 521 when the user already have a running session. My issue is httpd automatically maps this 521 error code to a 500 (internal server error) and then my client can not handle it properly. I have tried to disable ProxyErrorOverride, to remove the /error/HTTP_INTERNAL_SERVER_ERROR.html.var but it does not changes anything. How can I ask httpd to not change anything to the proxied message? <IfModule proxy_module> ProxyPass /context1 http://127.0.0.1:8001/context1 ProxyPass /context2 http://127.0.0.1:8002/context2 ProxyPreserveHost Off ProxyErrorOverride Off </IfModule> Thanks in advance httpd 2.2.22 (Win32) mod_ssl tomcat 7.25 windows 7 64-bits