diff --git a/doc/README.rst b/doc/README.rst
index 413428451..92db83b49 100644
--- a/doc/README.rst
+++ b/doc/README.rst
@@ -5,6 +5,14 @@ Included documents:
 - developer reference guide(devref)
 - man pages
 
+Dependencies
+------------
+Building this documentation can be done in a regular Nova development
+environment, such as the virtualenv created by ``run_tests.sh`` or
+``tools/install_venv.py``.  A leaner but sufficient environment can be
+created by starting with one that is suitable for running Nova (such
+as the one created by DevStack) and then using pip to install
+oslo.sphinx.
 
 Building the docs
 -----------------