When the h2 module is enabled and a client contacts Apache using HTTP/2, the server will send back a 411 error when the OPTIONS method is used without a body and without a Content-Length specified. This is not the case for HTTP/1.1, and accessing the same resource over HTTP/1.1 works fine. https://tools.ietf.org/html/rfc7230#section-3.3.2 specifies that: A user agent SHOULD send a Content-Length in a request message when no Transfer-Encoding is sent and the request method defines a meaning for an enclosed payload body. For example, a Content-Length header field is normally sent in a POST request even when the value is 0 (indicating an empty payload body). A user agent SHOULD NOT send a Content-Length header field when the request message does not contain a payload body and the method semantics do not anticipate such a body. (SHOULD, not MUST)
Sorry for the late reply. Using curl, all seems fine: curl -i --insecure -X OPTIONS https://test.example.org:12346/ HTTP/2 200 date: Sat, 28 Apr 2018 11:22:38 GMT server: Apache/2.5.1-dev (Unix) OpenSSL/1.0.2o allow: POST,OPTIONS,HEAD,GET,TRACE content-length: 0 content-type: httpd/unix-directory Do you have any more information on how to generate the request? A server log with LogLevel http2:trace2 might also help. Thanks!