diff --git a/Dockerfile b/Dockerfile
index fb795c0..d891bce 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 FROM ubuntu
 
-RUN apt-get update \
+RUN apt-get update -y \
     && apt-get install -y wget firefox xfce4 vnc4server
 ENV DISPLAY=":1" VNC_COL_DEPTH=24 VNC_RESOLUTION=1280x800 VNC_PW=xiaosong
 RUN mkdir /root/.vnc/ \