diff --git a/src/websock/WebsockUtil.cpp b/src/websock/WebsockUtil.cpp
index 6cd6b19d..e3dc4b57 100644
--- a/src/websock/WebsockUtil.cpp
+++ b/src/websock/WebsockUtil.cpp
@@ -26,7 +26,9 @@ namespace xo {
                 CASE(LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS);
                 CASE(LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS);
                 CASE(LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION);
+#ifdef OBSOLETE // at least on osx w/ nixpkgs dd868b7bd4d1407d607da0d1d9c5eca89132e2f7
                 CASE(LWS_CALLBACK_OPENSSL_CONTEXT_REQUIRES_PRIVATE_KEY);
+#endif
                 CASE(LWS_CALLBACK_SSL_INFO);
                 CASE(LWS_CALLBACK_OPENSSL_PERFORM_SERVER_CERT_VERIFICATION);
                 CASE(LWS_CALLBACK_SERVER_NEW_CLIENT_INSTANTIATED);