"Cannot afford transaction" version 0.7 clightning

Listfunds shows me:

963692 satoshi available to fund channels
6280512 satoshi owned in channels
14832105 satoshi total channel capacity


When I try to fund a channel with 400000 I get:

lightning-cli fundchannel 02b414e4e29a685b8699152be47a0420fa3c8ab59629d2da2d6c0a95c582636350 400000
{ "code" : 301, "message" : "Cannot afford transaction" }


Why?
Could it be that the outputs depicted in listfunds do not have yet enough confirmations? Maybe you got them after you closed a channel and c-lightning did not allow you to use them right away. Could you check again?