diff --git a/requirements.txt b/requirements.txt
index be610b1..8bae217 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,4 +5,5 @@ tensorflow>=1.10
 pandas>=0.23.4
 scikit-learn>=0.19.2
 scipy>=1.1.0
-matplotlib>=2.2.3
\ No newline at end of file
+matplotlib>=2.2.3
+protobuf>=6.33.5 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file