Copy one directory after another

Hello everybody,
currently I am migrating from one provider to another. It bothers me a bit that rclone does not copy the contents of one directory and then starting to copy the next directory. Currently there seems to be no order which file in which directory is copied first. Is there a way to force rclone to copy the content of one directory and if it has finished this, start with the content of the next directory?
Thank you for your answers in advance!

--transfers 1 will do that. It will slow stuff down though so I’m not sure it is worth it. YMMV.