diff --git a/README.md b/README.md
index 9894d950..a3b72bc5 100644
--- a/README.md
+++ b/README.md
@@ -139,8 +139,11 @@ Optional.
 
 Shell command to run before building the wheel. This option allows you to run a command in **each** Python environment before the `pip wheel` command. This is useful if you need to set up some dependency so it's available during the build.
 
+If dependencies are required to build your wheel (for example if you include a header from a Python module), set this to `{pip} install .`, and the dependencies will be installed automatically by pip. However, this means your package will be built twice - if your package takes a long time to build, you might wish to manually list the dependencies here instead.
+
 The active Python binary can be accessed using `{python}`, and pip with `{pip}`. These are useful when you need to write `python3` or `pip3` on a Python 3.x build.
 
+Example: `{pip} install .`  
 Example: `{pip} install pybind11`
 
 Platform-specific variants also available: