diff --git a/docs/requirements.txt b/docs/requirements.txt
index a77aa8cf7d..d9cbc647a1 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -3,3 +3,9 @@ sphinx-rtd-theme
 recommonmark
 sphinxcontrib-svg2pdfconverter
 sphinx_github_changelog
+
+# for gen_from_riscv_config
+mako
+mdutils
+pyyaml
+rstcloth