diff --git a/scripts/driver.requirements.txt b/scripts/driver.requirements.txt
index 17569bb..38838f5 100644
--- a/scripts/driver.requirements.txt
+++ b/scripts/driver.requirements.txt
@@ -1,10 +1,16 @@
 # Python package requirements for driver implementers.
 
+# Jinja2 <3.0 needs an older version of markupsafe, but does not
+# declare it.
+#   https://github.com/pallets/markupsafe/issues/282
+#   https://github.com/pallets/jinja/issues/1585
+markupsafe < 2.1
+
 # Use the version of Jinja that's in Ubuntu 20.04.
 # See https://github.com/ARMmbed/mbedtls/pull/5067#discussion_r738794607 .
 # Note that Jinja 3.0 drops support for Python 3.5, so we need to support
 # Jinja 2.x as long as we're still using Python 3.5 anywhere.
 Jinja2 >= 2.10.1
-# Jinja2 >=2.10, <<3.0 needs a separate package for type annotations
+# Jinja2 >=2.10, <3.0 needs a separate package for type annotations
 types-Jinja2