diff --git a/python-requirements.txt b/python-requirements.txt
index f56b0aa1..ea402c40 100644
--- a/python-requirements.txt
+++ b/python-requirements.txt
@@ -10,3 +10,6 @@ git+https://github.com/lowRISC/fusesoc.git@ot
 
 pyyaml
 mako
+
+# Needed by dvsim.py (not actually used in Ibex)
+premailer