diff --git a/requirements.txt b/requirements.txt
index 48adc93..09683d5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
+jinja2==3.0.3
 jupyter-book==0.12.1
 sphinx==3.5.4
 sphinx_rtd_theme==1.0.0