diff --git a/docs/requirements.txt b/docs/requirements.txt
index 56a844ef4f..b69ce569e0 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -6,4 +6,5 @@ pandoc
 docutils
 git+https://github.com/PytorchLightning/lightning_sphinx_theme.git
 sphinxcontrib-fulltoc
-sphinxcontrib-mockautodoc
\ No newline at end of file
+sphinxcontrib-mockautodoc
+PackageFinder
\ No newline at end of file