diff --git a/Dockerfile b/Dockerfile
index 6ba2aa8..517d4e8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 # Use ubuntu 16.04
 FROM ubuntu:16.04
-EXPOSE 2020
+EXPOSE 20202
 RUN apt-get update
 
 # install socat editor ssh
@@ -25,6 +25,6 @@ RUN chmod 775 /chall/version002
 
 # Run Service
 
-RUN echo '#!/bin/bash'"\n(socat TCP-LISTEN:2020,reuseaddr,fork EXEC:"/chall/version002,su=nobody")" > /var/tmp/.start.sh && chmod +x /var/tmp/.start.sh
+RUN echo '#!/bin/bash'"\n(socat TCP-LISTEN:20202,reuseaddr,fork EXEC:"/chall/version002,su=nobody")" > /var/tmp/.start.sh && chmod +x /var/tmp/.start.sh
 
 CMD ["/var/tmp/.start.sh"]