diff --git a/requirements.txt b/requirements.txt
index 7c69cc2..639c317 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -62,7 +62,7 @@ Mako==1.0.7
 Markdown==3.0.1
 MarkupSafe==1.1.0
 matplotlib==3.0.2
-mistune==0.8.4
+mistune==2.0.3
 mlagents==0.4.0
 mlagents-envs==0.8.1
 more-itertools==7.0.0