diff --git a/requirements-to-freeze.txt b/requirements-to-freeze.txt
index 1b3a6e86..899eaab9 100644
--- a/requirements-to-freeze.txt
+++ b/requirements-to-freeze.txt
@@ -1 +1,2 @@
-sphinx
\ No newline at end of file
+sphinx
+urllib3>=2.5.0 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file