Can't launch gnome-system-monitor 40.0 in non-GNOME environments: gtk_window_set_titlebar() is not supported for HdyWindow

Just after the update to gnome-system-monitor version 40.0 on my Archlinux system, I am unable to launch it. When I run it from the terminal, I get:

$ gnome-system-monitor

(gnome-system-monitor:7751): Gtk-CRITICAL **: 13:45:15.119: gtk_box_pack: assertion '_gtk_widget_get_parent (child) == NULL' failed

(gnome-system-monitor:7751): Handy-ERROR **: 13:45:15.228: gtk_window_set_titlebar() is not supported for HdyWindow
Trace/breakpoint trap (core dumped)

Using xfce4 4.16