diff --git a/Dockerfile b/Dockerfile
index fd42274..7ee1216 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,7 +18,7 @@ WORKDIR /install
 
 RUN pip install --prefix="/install" --no-warn-script-location \
 # gunicorn is used for launching netbox
-      gunicorn \
+      'gunicorn<20.0.0' \
       greenlet \
       eventlet \
 # napalm is used for gathering information from network devices