Sorry, I mixed some stuff up. ssh-add gives me an OpenSSH window instead of the ksshaskpass unless I set SSH_ASKPASS. The thing originally had a problem though was with git, accessing a remote over HTTP. It also uses SSH_ASKPASS when asking for a password for HTTP, so that's why I mixed them up. Anyway, adding the symlink as you suggested fixes ssh-add, though it does not work for git with HTTP.