jupyter_client: prompt_toolkit breaks redirected input

I believe that prompt_toolkit has broken this use of jupyter-client:

$ jupyter console --kernel metakernel_python < generate_help.py
Traceback (most recent call last):
  File "/usr/local/bin/jupyter-console", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.4/dist-packages/jupyter_core/application.py", line 267, in launch_instance
    return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
  File "/usr/local/lib/python3.4/dist-packages/traitlets/config/application.py", line 595, in launch_instance
    app.initialize(argv)
  File "<decorator-gen-113>", line 2, in initialize
  File "/usr/local/lib/python3.4/dist-packages/traitlets/config/application.py", line 74, in catch_config_error
    return method(app, *args, **kwargs)
  File "/usr/local/lib/python3.4/dist-packages/jupyter_console/app.py", line 137, in initialize
    self.init_shell()
  File "/usr/local/lib/python3.4/dist-packages/jupyter_console/app.py", line 110, in init_shell
    client=self.kernel_client,
  File "/usr/local/lib/python3.4/dist-packages/traitlets/config/configurable.py", line 412, in instance
    inst = cls(*args, **kwargs)
  File "/usr/local/lib/python3.4/dist-packages/jupyter_console/ptshell.py", line 252, in __init__
    self.init_prompt_toolkit_cli()
  File "/usr/local/lib/python3.4/dist-packages/jupyter_console/ptshell.py", line 404, in init_prompt_toolkit_cli
    self.pt_cli = CommandLineInterface(app, eventloop=self._eventloop)
  File "/usr/local/lib/python3.4/dist-packages/prompt_toolkit/interface.py", line 81, in __init__
    self.input = input or StdinInput(sys.stdin)
  File "/usr/local/lib/python3.4/dist-packages/prompt_toolkit/input.py", line 67, in __init__
    assert self.stdin.isatty()
AssertionError