diff --git a/requirements.txt b/requirements.txt
index df088d8b3aa59a08370688456e91136b325ee0f9..cd61bdfb81191bc0f19f6fa8c658b49ffad87d20 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,3 +9,4 @@ sphinx
 sphinx-rtd-theme
 sphinx-autoapi
 twine
+numpydoc