HTTP RPC API Key Export 404

I am trying to export a key from my local ipfs node to a specified path on my machine.

I am able to use key/gen, key/import, key/list, and key/rm without issue. I am also able to use the command line key export, but I would prefer to use the HTTP API for my use case.

However, running the following returns a 404 error.

curl -X POST "http://127.0.0.1:5001/api/v0/key/export?arg=mykey"
404 page not found

What should be done to resolve this issue? I would like to use the output argument, but the error shows up even without optional arguments.

My node is running go-ipfs.
ipfs version 0.11.0.

The key export functionality is not available through the API. I am not sure if this is because of security considerations or because the implementation spits it to disk and would return an empty API response.