diff --git a/Makefile b/Makefile
index 28fc9a7..10eb1c3 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,8 @@ BASEDIR=$(CURDIR)
 DOCDIR=$(BASEDIR)/docs
 
 install:
-	pip install mkdocs mkdocs-material mkdocs-bootswatch
+	pip install mkdocs==0.16.3
+	pip install mkdocs-material==1.12.2
 
 link:
 	ln -sf $(BASEDIR)/README.md $(DOCDIR)/index.md