Building 7.1.3 with PL/Perl support on RedHat

I have compiled PostgreSQL 7.1.3 on RedHat 7.1.
There seems to be a problem with PL/Perl:

make[3]: Entering directory
`/data/download/postgres/postgresql-7.1.3/src/pl/plperl'
make -f Makefile all
make[4]: Entering directory
`/data/download/postgres/postgresql-7.1.3/src/pl/plperl'
*****
* Cannot build PL/Perl because libperl is not a shared library.
* Skipped.
*****
make[4]: Leaving directory
`/data/download/postgres/postgresql-7.1.3/src/pl/plperl'
make[3]: Leaving directory
`/data/download/postgres/postgresql-7.1.3/src/pl/plperl'
make[2]: Leaving directory
`/data/download/postgres/postgresql-7.1.3/src/pl'
make[1]: Leaving directory
`/data/download/postgres/postgresql-7.1.3/src'
All of PostgreSQL successfully made. Ready to install.

I used:
[hs(at)athlon postgresql-7.1.3]$ ./configure --prefix=/tmp/postgres
--with-perl --with-python --with-tcl --enable-multibyte
--datadir=/tmp/pgdata/

Hans