diff --git a/docs/README.rst b/docs/README.rst
index baae43b..3c3448a 100644
--- a/docs/README.rst
+++ b/docs/README.rst
@@ -52,6 +52,14 @@ API documentation. This build target skips that.
 
 You can run ``make help`` to see information on all possible make targets.
 
+To save time,
+the make targets above only proceess the files that have been changed since the
+previous docs build.
+To remove the previous docs build you can use ``make clean``.
+You can also combine ``clean`` with other targets,
+for example,
+``make clean html`` will do a complete rebuild of the docs.
+
 
 Continuous Integration
 ----------------------