diff --git a/horizon/openstack-dashboard.conf b/horizon/openstack-dashboard.conf
index 2dc4b2c..dfa7b5b 100644
--- a/horizon/openstack-dashboard.conf
+++ b/horizon/openstack-dashboard.conf
@@ -12,6 +12,7 @@
     SSLEngine On
     SSLCertificateFile "/certs/merlin.hpc.rug.nl.crt"
     SSLCertificateKeyFile "/certs/merlin.hpc.rug.nl.key"
+    SSLCACertificateFile "/certs/DigiCertCA.crt"
     SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown
 
     # HTTP Strict Transport Security (HSTS) enforces that all communications
diff --git a/keystone/apache-keystone.conf b/keystone/apache-keystone.conf
index 99e0111..f744d37 100644
--- a/keystone/apache-keystone.conf
+++ b/keystone/apache-keystone.conf
@@ -16,6 +16,7 @@ Alias "/secure" "/var/www/html/secure"
     SSLEngine on
     SSLCertificateFile "/certs/merlin.hpc.rug.nl.crt"
     SSLCertificateKeyFile "/certs/merlin.hpc.rug.nl.key"
+    SSLCACertificateFile "/certs/DigiCertCA.crt"
     UseCanonicalName On
     WSGIScriptAlias / /usr/bin/keystone-wsgi-public
     WSGIDaemonProcess keystone-public processes=5 threads=1 user=keystone group=keystone display-name=%{GROUP}
@@ -79,6 +80,7 @@ Alias "/secure" "/var/www/html/secure"
     SSLEngine on
     SSLCertificateFile "/certs/merlin.hpc.rug.nl.crt"
     SSLCertificateKeyFile "/certs/merlin.hpc.rug.nl.key"
+    SSLCACertificateFile "/certs/DigiCertCA.crt"
     UseCanonicalName On
     WSGIScriptAlias / /usr/bin/keystone-wsgi-admin
     WSGIDaemonProcess keystone-admin processes=5 threads=1 user=keystone group=keystone display-name=%{GROUP}