diff --git a/Dockerfile b/Dockerfile
index 647dea3..86ba80e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ RUN go get golang.org/x/tools/cmd/present
 
 COPY ./docker.slide /xe/docker.slide
 
-EXPOSE 3999
+EXPOSE 80
 
 WORKDIR /xe
-CMD present -http 0.0.0.0:3999
+CMD present -http 0.0.0.0:80