Error on wakeup after installing light-locker

I'm using XFCE on Arch Linux and I have Gnome installed too. I wanted to have the possibility of locking the session so I switched to lightdm from gdm and installed light-locker. Now every time I wake my laptop from sleep by opening the lid, I get the following error notification: GDBus.Error:org.freedesktop.login1.OperationinProgress: There's already a shutdown or sleep operation in progress dmesg does not reveal anything that seems related to this minor annoyance. This is no big deal but I would like to get rid of this notification. Any ideas where to look?