diff --git a/requirements-doc.txt b/requirements-doc.txt
index 47c813e83d..f4214a10d6 100644
--- a/requirements-doc.txt
+++ b/requirements-doc.txt
@@ -1,3 +1,4 @@
 mkdocs
 mkdocs-material
 mkdocs-material-extensions
+mike  # deploy several mkdocs site versions to github pages