diff --git a/requirements.txt b/requirements.txt
index 61b1c73..7b56344 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,3 +11,4 @@ nose==1.3.7
 python-dateutil==2.7.2
 python-dotenv==0.7.1
 gunicorn==19.7.1
+prompt-toolkit>=3.0.13 # not directly required, pinned by Snyk to avoid a vulnerability