php56-http2 error

[Horst Simon]

Hi 

I have php56 and http2 for php56 installed, but when I run php-v I get following errors:

PHP Warning:  PHP Startup: Unable to load dynamic library '/opt/local/lib/php56/extensions/no-debug-non-zts-20131226/http.so' - dlopen(/opt/local/lib/php56/extensions/no-debug-non-zts-20131226/http.so, 9): Symbol not found: _php_persistent_handle_abandon
  Referenced from: /opt/local/lib/php56/extensions/no-debug-non-zts-20131226/http.so
  Expected in: flat namespace
 in /opt/local/lib/php56/extensions/no-debug-non-zts-20131226/http.so in Unknown on line 0

Is there an error in http.so, or do I need to install additional extensions/libraries?

Kind Regards,
Horst