How to transpose command line arguments with emacs keybindings?

Using Bash, with emacs keybindings set, the transpose-words keybinding (M-t) doesn't transpose arguments, but "words" (by its own definition of words). So if I have this: vimdiff project-number-One/Vagrantfile project-number-Two/Vagrantfile.old and my cursor is between the first and second argument when I enter optiont, I instead end up with vimdiff project-number-One/project Vagrantfile-number-Two/Vagrantfile.old which is obviously not what I want. How can I transpose arguments?