SSL/TLS passphrase not being prompted for at startup

Hi,

OpenLDAP version: 2.4.40-8.el7.x86_64 OS: CentOS 7.0.1406

While starting openldap service with command line: systemctl start slapd, it does start well, but does not ask for passphrase of the TLS certificate included. The service listens on ports 636 and 389. When the first request over port 636 is received, the server prompts for passphrase in the console.

While this behavior is fine when I run slapd on an attached console, it stops me from running it as a system startup service.

Can somebody help me to make slapd to prompt for passphrase during startup?

Thanks and Regards, Raja.