diff --git a/Dockerfile b/Dockerfile
index fb38c0a..e988c43 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -80,3 +80,4 @@ VOLUME ["/import"]
 WORKDIR /import/
 # Start RStudio
 CMD /startup.sh
+EXPOSE 80
diff --git a/proxy.conf b/proxy.conf
index a04e359..b156cb7 100644
--- a/proxy.conf
+++ b/proxy.conf
@@ -1,19 +1,18 @@
 server {
-    # listen IE_PORT;
     listen 80;
     server_name localhost;
     access_log /var/log/nginx/localhost.access.log;
 
     # Some help from https://superuser.com/questions/689885/make-nginx-reverse-proxy-302-redirect-to-a-uri-sub-folder-instead-of-root
-    location ^~ /rstudio/IE_PORT/ {
+    location ^~ PROXY_PREFIX/rstudio/ {
         add_header 'Access-Control-Allow-Origin' '*'; # IE_CORS_ORIGIN
         add_header 'Access-Control-Allow-Credentials' 'true';
         add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
         add_header 'Access-Control-Allow-Headers' 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
 
         proxy_buffering off;
-        rewrite /rstudio/IE_PORT/(.*) /$1 break;
+        rewrite PROXY_PREFIX/rstudio/(.*) /$1 break;
         proxy_pass         http://127.0.0.1:8787;
-        proxy_redirect     http://127.0.0.1:8787/ /rstudio/IE_PORT/;
+        proxy_redirect     http://127.0.0.1:8787/ PROXY_PREFIX/rstudio/;
     }
 }
diff --git a/startup.sh b/startup.sh
index 594af9e..a8b8ede 100755
--- a/startup.sh
+++ b/startup.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 sed -i "s| '\*'; # IE_CORS_ORIGIN| '${CORS_ORIGIN}';|" /proxy.conf;
-sed -i "s/IE_PORT/${DOCKER_PORT}/" /proxy.conf;
+sed -i "s|PROXY_PREFIX|${PROXY_PREFIX}|" /proxy.conf;
 cp /proxy.conf /etc/nginx/sites-enabled/default
 
 # The RStudio image starts as privileged user. The parent Galaxy server is
@@ -40,6 +40,6 @@ GALAXY_URL=$GALAXY_URL
 " > /etc/profile.d/galaxy.sh
 
 # Launch traffic monitor
-monitor_traffic.sh &
+/monitor_traffic.sh &
 # And nginx in foreground mode.
 nginx -g 'daemon off;'