diff --git a/requirements.txt b/requirements.txt
index a0f5fe5..208ea2b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,3 +7,4 @@ scikit_learn==0.22.1
 flask==1.1.1
 chatterbot==1.0.5
 chatterbot-corpus==1.2.0
+urllib3>=1.26.5 # not directly required, pinned by Snyk to avoid a vulnerability