System Monitor Compnent not loading

I’m getting the following erros when trying to use system monitor on a Raspberry Pi

16-10-03 00:59:37 homeassistant.components.sensor: Error while setting up platform systemmonitor
Traceback (most recent call last):
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/helpers/", line 107, in _setup_platform
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/components/sensor/", line 59, in setup_platform
dev.append(SystemMonitorSensor(resource['type'], resource['arg']))
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/components/sensor/", line 74, in __init__
  File "/srv/hass/hass_venv/lib/python3.4/site-packages/homeassistant/components/sensor/", line 140, in update
self._state = psutil.net_if_addrs()[self.argument][0][1]
KeyError: 'wlan0'

Sensor configuration:

sensor 4:
  platform: systemmonitor
    - type: memory_free
    - type: processor_use
    - type: since_last_boot
    - type: ipv4_address
      arg: wlan0
    - type: last_boot

I have no idea where to start fixing it.

I figured it out… I changed my configuration and decided to use eth0 instead of waln0… forgot to change that in the YAML file.