forcing SSL

In order to ensure all user are making SSL connection to the database,
in the file pg_hba.conf, I change all the first columns into "hostssl"
such that there is neither "host" nor "local" left.

However, when I try to use a program written in Tcl to access the
database, even without the option "requiressl=1" for "pg_connect", the
program can still make connection to the database.

(With the option "requiressl=1" present for "pg_connect", my program
can also connect the database successfully)

May I know what the problem is and how to ensure incoming SSL
connection?

Thank you