TCP stream support

I have installed Kong 1.3 enterprise edition and am trying use TCP stream support based on this link https://konghq.com/blog/tcp-stream-support-kong/

After configuring stream_listen and attempting restart. I see
nginx: [error] init_by_lua error: /usr/local/share/lua/5.1/kong/tools/utils.lua:618: /usr/local/openresty/lualib/resty/kong/tls.lua:21: unsuppo
rted subsystem: stream
stack traceback:
[C]: in function ‘error’
/usr/local/share/lua/5.1/kong/tools/utils.lua:618: in function ‘load_module_if_exists’
/usr/local/share/lua/5.1/kong/db/dao/plugins.lua:151: in function ‘load_plugin_handler’
/usr/local/share/lua/5.1/kong/db/dao/plugins.lua:234: in function ‘load_plugin’
/usr/local/share/lua/5.1/kong/db/dao/plugins.lua:281: in function ‘load_plugin_schemas’
/usr/local/share/lua/5.1/kong/init.lua:434: in function ‘init’
init_by_lua:11: in main chunk

what is missing in my config?