There is a (new) Secure SSL forward proxy in my corporate. It requires a client to perform: TCP handshake + TLS handshake + followed by http CONNECT request Now this works fine when we simulate proxy connection using curl, for instance: #curl --head -v -ik --proxy https://proxy.mydomain.com:8443 https://www.google.com/ However when setting up FF for proxy configuration, and adding proxy details under HTTPS Proxy, cant connect via that proxy. Looking at network dump we do see that FF is doing: TCP handshake + straight away sends http CONNECT request - and its missing to initiate TLS handshake.... Is there anyway at all to configure FF to connect via secure SSL proxy ?