Error starting 1.0.15 with SSL_DISABLE=No

When starting Dovecot 1.0.15 after building it from source using the standard procedure, I receive the following message when starting, even though SLL_DISABLE=No:

Error: SSL support not compiled in but ssl_disable=no Fatal: Invalid configuration in /usr/local/etc/dovecot.conf

How is SSL support configured and built in? I know it has something to do with the --SSL_CFLAGS flag.