diff --git a/docker/kolab/kolab-init.sh b/docker/kolab/kolab-init.sh
--- a/docker/kolab/kolab-init.sh
+++ b/docker/kolab/kolab-init.sh
@@ -31,5 +31,6 @@
 ./20-add-alias-attribute-index.sh && echo "20 done"
 ./21-adjust-postfix-config.sh && echo "21 done"
 ./23-patch-system.sh && echo "23 done"
+./24-roundcubeconfig.sh && echo "24 done"
 
 touch /tmp/kolab-init.done
diff --git a/docker/kolab/utils/24-roundcubeconfig.sh b/docker/kolab/utils/24-roundcubeconfig.sh
new file mode 100755
--- /dev/null
+++ b/docker/kolab/utils/24-roundcubeconfig.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+sed -i -r -e "s/\$config['kolab_files_url'] =.*$/\$config['kolab_files_url'] = 'https://' \. \$_SERVER['HTTP_HOST'] . '/chwala/';/g" /etc/roundcubemail/kolab_files.inc.php
+
+sed -i -r -e "s/\$config['kolab_invitation_calendars'] =.*$/\$config['kolab_invitation_calendars'] = true;/g" /etc/roundcubemail/calendar.inc.php