diff --git a/requirements.txt b/requirements.txt
index 542f538..b158a5a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@ MarkupSafe==1.1.1
 WTForms==2.0.2
 Werkzeug==0.16.0
 gevent==1.4.0
-greenlet==0.4.15
+greenlet==0.4.16
 isodate==0.6.0
 itsdangerous==1.1.0
 pytz==2019.3