diff --git a/docs/requirements.txt b/docs/requirements.txt
index aa621f5..f04d06f 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -30,3 +30,4 @@ w3lib==1.22.0; python_full_version >= "3.6.0"
 websockets==8.1; python_full_version >= "3.6.1" and python_full_version < "4.0.0"
 werkzeug==1.0.1; (python_version >= "2.7" and python_full_version < "3.0.0") or (python_full_version >= "3.5.0")
 yarl==1.6.3; python_version >= "3.6"
+sphinx_autodoc_typehints