diff --git a/Dockerfile b/Dockerfile
index 36198f1..6c90c05 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 FROM ubuntu:trusty
 
-ENV GUNICORN_WORKERS=4
+ENV WEB_CONCURRENCY=4
 
 ADD . /httpbin
 
@@ -8,4 +8,4 @@ RUN apt-get update -y && apt-get -y install python-pip && pip install gunicorn &
 
 EXPOSE 8080
 
-CMD gunicorn -w "$GUNICORN_WORKERS" -b 0.0.0.0:8080 httpbin:app
+CMD gunicorn -b 0.0.0.0:8080 httpbin:app