AssertionError: PORT is not a number when explicitly passing a string value to ssh_address_or_host

[p0lm]

When explicitly passing ssh_address_or_host a string value AssertionError: PORT is not a number is thrown.

sshtunnel.open_tunnel('1.1.1.1', **kwargs) # works
sshtunnel.open_tunnel(ssh_address_or_host='1.1.1.1', **kwargs) # fails

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "(...)\site-packages\sshtunnel.py", line 1625, in open_tunnel
    forwarder = SSHTunnelForwarder(*args, **kwargs)
  File "(...)\site-packages\sshtunnel.py", line 864, in __init__
    check_address(ssh_address_or_host)
  File "(...)\site-packages\sshtunnel.py", line 109, in check_address
    check_port(address[1])
  File "(...)\site-packages\sshtunnel.py", line 84, in check_port
    assert isinstance(port, int), 'PORT is not a number'
AssertionError: PORT is not a number