diff --git a/README.md b/README.md
index 123992c4..068525b7 100644
--- a/README.md
+++ b/README.md
@@ -55,9 +55,10 @@ The GUI's HTML file is automatically built when building the LOOT GUI binary, bu
 
 ## Building The Documentation
 
-The documentation is built using [Doxygen](http://www.stack.nl/~dimitri/doxygen/), [Breathe](https://breathe.readthedocs.io/en/latest/) and [Sphinx](http://www.sphinx-doc.org/en/stable/). Install them (Breathe and Sphinx support Python 2 and 3) and make sure they're accessible from your `PATH`, then run:
+The documentation is built using [Doxygen](http://www.stack.nl/~dimitri/doxygen/), [Breathe](https://breathe.readthedocs.io/en/latest/) and [Sphinx](http://www.sphinx-doc.org/en/stable/). Install Doxygen and Python (2 or 3) and make sure they're accessible from your `PATH`, then run:
 
 ```
+pip install -r docs/api/requirements.txt
 sphinx-build -b html docs build/docs/html
 ```
 
diff --git a/docs/api/requirements.txt b/docs/api/requirements.txt
index cd6467ed..b98be4a2 100644
--- a/docs/api/requirements.txt
+++ b/docs/api/requirements.txt
@@ -1 +1,3 @@
+sphinx==1.4.9
+sphinx_rtd_theme
 breathe