diff --git a/requirements.txt b/requirements.txt
index e5effb3..e3ece18 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -55,7 +55,7 @@ Markdown==2.6.11
 MarkupSafe==1.0
 matplotlib==2.2.2
 mccabe==0.6.1
-mistune==0.8.3
+mistune==2.0.3
 music21==5.1.0
 nbconvert==5.3.1
 nbformat==4.4.0