diff --git a/requirements.txt b/requirements.txt
index d7cb03e85..438f818d7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,9 +4,9 @@ colour
 scikit-image
 gevent
 eventlet
-gunicorn
-gunicorn[gevent]
-gunicorn[eventlet]
+gunicorn==19.9.0
+gunicorn[gevent]==19.9.0
+gunicorn[eventlet]==19.9.0
 boto3
 rasterio>=1.0.9
 ruamel.yaml