diff --git a/requirements.txt b/requirements.txt
index 2024cf92..7a4fa0e0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -23,7 +23,7 @@ jinja2==2.7
 libmodernize==0.5
 markdown==2.6.2
 markdown2==2.2.1
-markupsafe
+markupsafe==3.0.3
 matplotlib==1.4.0
 mccabe==0.4.0
 midiutil