diff --git a/Step-4-TrainingOverBLE/training/requirements.txt b/Step-4-TrainingOverBLE/training/requirements.txt
index ed3414e..25e75b6 100644
--- a/Step-4-TrainingOverBLE/training/requirements.txt
+++ b/Step-4-TrainingOverBLE/training/requirements.txt
@@ -2,4 +2,5 @@ numpy
 gym
 keras-rl
 theano
-pyserial
\ No newline at end of file
+pyserial
+pillow>=8.1.1 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file