diff --git a/requirements_dev.txt b/requirements_dev.txt
index 5a728014e..529d9640f 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -14,3 +14,4 @@ rqrisk >=0.0.9
 h5py
 matplotlib >=1.5.1 ; python_version >= '3.6'
 matplotlib >=1.5.1,<=3.0.3 ; python_version == '3.5'
+pillow>=10.3.0 # not directly required, pinned by Snyk to avoid a vulnerability