diff --git a/requirements.txt b/requirements.txt
index e4c5de6..0e61640 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,6 @@
 click==7.1.2
 Flask==1.1.2
+gunicorn==20.1.0
 itsdangerous==1.1.0
 Jinja2==2.11.3
 MarkupSafe==1.1.1