I have the test.pl website and the hosting.test.pl subdomain. test.pl supports hosting.test.pl. I changed DocumentRoot hosting.test.pl to test.pl and activated Let's Encrypt for hosting.test.pl . Code: DocumentRoot /var/www/clients/client40/web52/web <Directory /var/www/clients/client40/web52/web> Options +Includes +FollowSymlinks +Indexes AllowOverride All Require all granted </Directory> Everything works fine, but hosting.test.pl shows the PHP 5.6 version and the PHP 7.1 version for the subdomain is set in ISPconfig. PHP 7.1 is also enabled for test.pl. Why in this case, hosting.test.pl uses PHP 5.6? How to enable PHP 7.1 for subdomain?