diff --git a/requirements-app.txt b/requirements-app.txt
index fd05e0a1a..d54f17b21 100644
--- a/requirements-app.txt
+++ b/requirements-app.txt
@@ -12,7 +12,7 @@ pyexcel-io==0.5.11
 pyexcel-xls==0.5.8
 pyexcel-xlsx==0.5.6
 pyexcel-ods3==0.5.3
-pytz==2018.7
+pytz==2018.9
 gunicorn==19.7.1  # >19.8 stops eventlet workers after a timeout
 eventlet==0.24.1
 notifications-python-client==5.2.0