Enable X-Frame-Options in proxy SSL Apache

Hi, I am configuring Apache as a SSL Proxy (apart of answering non-SSL request on 82 port). I do this since I have Varnish running on 80 port for caching. This has been working fine for more than 2 years. I can set RequestHeader as X-Forwarded-Proto or X-Forwarded-Port. I have enabled X-Frame-Options in tweak options but still getting X-Frame-Options deny in the headers although I have added this entry in the SSL proxy for a website: RequestHeader set X-Frame-Options "sameorigin" What am I doing wrong?