diff --git a/requirements.txt b/requirements.txt
index fd4f6d2..a170625 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,4 +3,5 @@ numpy>=1.9.3
 matplotlib>=3.1.1
 peakdet
 scipy
+pillow>=10.3.0 # not directly required, pinned by Snyk to avoid a vulnerability
 fonttools>=4.43.0 # not directly required, pinned by Snyk to avoid a vulnerability