This is a simplified reproducer that does not actually perform OCSP check but you can see logging where it at least gets into OCSP code: 1. Install httpd and mod_ssl 2. Add the following configurations in ssl.conf but outside of the VirtualHost. I did have to create a CA and client cert but the Responder URL goes to nowhere. SSLCACertificateFile /tmp/cacert.crt SSLVerifyClient require SSLVerifyDepth 1 SSLOCSPEnable On SSLOCSPDefaultResponder http: //localhost:9999/ SSLOCSPOverrideResponder On 3. Send request with a certificate signed by the /tmp/cacert.crt # curl -I -E ./cert.crt:test --key ./privkey.key -k https: //localhost/ HTTP/1.1 200 OK 4. The request above succeeds but should not because the OCSP responder is unreachable and cert cannot be validated.