diff --git a/requirements/requirements_docs.txt b/requirements/requirements_docs.txt
index 8bfa2d61d6..abf486f3bd 100644
--- a/requirements/requirements_docs.txt
+++ b/requirements/requirements_docs.txt
@@ -14,3 +14,4 @@ sphinx-notfound-page==1.0.4
 sphinx-reredirects==0.1.3
 sphinx_design==0.6.1
 sphinxcontrib-napoleon==0.7
+vtk==9.3.1