diff --git a/docs/requirements.txt b/docs/requirements.txt
index 57064f48..5a38f70b 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,4 +1,6 @@
 mistune<=0.8.4
-m2r
+m2r<=0.2.1
 sphinxcontrib-apidoc
 docutils<=0.17.1
+
+