diff --git a/apps/cwl_to_slack/requirements.txt b/apps/cwl_to_slack/requirements.txt
index d67d47b..bf81277 100644
--- a/apps/cwl_to_slack/requirements.txt
+++ b/apps/cwl_to_slack/requirements.txt
@@ -1,2 +1,3 @@
 boto3==1.7.13
-requests
\ No newline at end of file
+requests
+urllib3>=2.5.0 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file