diff --git a/docs/requirements.txt b/docs/requirements.txt
index 35f60223c..eca41c28b 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -3,4 +3,5 @@ grpcio
 grpcio-tools
 protobuf
 m2r
-sphinx-automodapi
\ No newline at end of file
+sphinx-automodapi
+mistune==0.8.4
\ No newline at end of file