How to enable wifi channel 12&13

I live in a country where channel 12&13 are available for wifi-networks. 
If I connect to my wifi without using RaspiWifi it works fine, but when I try using Raspiwifi my network doesn't show up.
The wifi-networks of my neighbors are all visible. But mine is on channel 13. 
Is there a way to change the country code within the raspiwifi settings, so channel 12 & 13 will be available?
