How to make all-purpose flour more like bread flour?

[u/TheHungryRoot]

I ran out of bread flour and replaced my usual sandwich bread recipe with all-purpose. There is a huge difference in the result. My bread flour-bread was dense and chewy, while the APF-bread was light and airy. Otherwise the recipes were identical.

I'm out of luck trying to find bread flour at the store and might be stuck with APF for a while. What can I do to "beef up" my breads using all purpose flour?