PostgreSQL 9.5 and PL/Ruby install problem(Centos 6 64 bit)

Installing on Centos 6 PostgreSQL 9.5 (64 bit) ; ruby 1.8
and get from https://pkgs.org/centos-6/epel-x86_64/postgresql-plruby-0.5.3-4.el6.x86_64.rpm.html - plruby libraries(postgresql-plruby-0.5.3-4.el6.x86_64).
Additional installed postgresql95-libs (postgresql95-libs-9.5.2-1PGDG.rhel6.x86_64)
Trying add plruby to PostgreSQL -
create function plruby_call_handler() returns language_handler
as '/usr/lib64/ruby/site_ruby/1.8/x86_64-linux/plruby.so'
language 'c';
The follows error appears - could not load library "/usr/lib64/ruby/site_ruby/1.8/x86_64-linux/plruby.so": /usr/lib64/ruby/site_ruby/1.8/x86_64-linux/plruby.so: undefined symbol: FunctionCall3
Add libraries path to LD_LIBRARY+PATH environment variable, recreating ld .so.cache doesn't change result - the same error appears.

What could be a problem!?
Thanks in advance for any replies or tips how it could be done...
Hanan Brener

Database and Data Collection Team Leader

Allot Communications