diff --git a/docs/README.rst b/docs/README.rst
index 733af2af4..af8bf4297 100644
--- a/docs/README.rst
+++ b/docs/README.rst
@@ -15,7 +15,7 @@ and all its dependencies run
 
 ::
 
-    pip install 'Sphinx >= 1.3'
+    pip install 'Sphinx >= 1.3' sphinx_rtd_theme
 
 
 Compile the documentation