diff --git a/app/ch16_mongodb/final/requirements-dev.txt b/app/ch16_mongodb/final/requirements-dev.txt
index 33814720..afd955fb 100644
--- a/app/ch16_mongodb/final/requirements-dev.txt
+++ b/app/ch16_mongodb/final/requirements-dev.txt
@@ -6,3 +6,5 @@ pytest
 pytest-cov
 webtest
 pytest-clarity
+mako>=1.2.2 # not directly required, pinned by Snyk to avoid a vulnerability
+waitress>=3.0.1 # not directly required, pinned by Snyk to avoid a vulnerability