diff --git a/requirements-old.txt b/requirements-old.txt
index b31c620..0f9a079 100644
--- a/requirements-old.txt
+++ b/requirements-old.txt
@@ -37,7 +37,7 @@ jupyterlab-widgets==1.0.0
 kiwisolver==1.3.1
 MarkupSafe==1.1.1
 matplotlib==3.3.4
-mistune==0.8.4
+mistune==2.0.3
 nbclient==0.5.2
 nbconvert==6.0.7
 nbformat==5.1.2