diff --git a/firefox/centos7/Dockerfile b/firefox/centos7/Dockerfile
index d1892c4c..c55f49d4 100644
--- a/firefox/centos7/Dockerfile
+++ b/firefox/centos7/Dockerfile
@@ -8,18 +8,18 @@ FROM centos:centos7
 MAINTAINER The CentOS Project <cloud-ops@centos.org>
 
 # Install the appropriate software
-RUN yum -y update; yum clean all
-RUN yum -y install epel-release; yum clean all
-RUN yum -y install x11vnc firefox xorg-x11-server-Xvfb xorg-x11-twm tigervnc-server xterm xorg-x11-font dejavu-sans-fonts dejavu-serif-fonts xdotool; yum clean all
+RUN yum -y update; yum clean all \
+    && yum -y install epel-release; yum clean all \
+    && yum -y install x11vnc firefox xorg-x11-server-Xvfb xorg-x11-twm tigervnc-server xterm xorg-x11-font dejavu-sans-fonts dejavu-serif-fonts xdotool; yum clean all
 
 # Add the xstartup file into the image
 ADD ./xstartup /
 
-RUN mkdir /.vnc
-RUN x11vnc -storepasswd 123456 /.vnc/passwd
-RUN  \cp -f ./xstartup /.vnc/.
-RUN chmod -v +x /.vnc/xstartup
-RUN sed -i '/\/etc\/X11\/xinit\/xinitrc-common/a [ -x /usr/bin/firefox ] && /usr/bin/firefox &' /etc/X11/xinit/xinitrc
+RUN mkdir /.vnc \
+    && x11vnc -storepasswd 123456 /.vnc/passwd \
+    &&  \cp -f ./xstartup /.vnc/. \
+    && chmod -v +x /.vnc/xstartup \
+    && sed -i '/\/etc\/X11\/xinit\/xinitrc-common/a [ -x /usr/bin/firefox ] && /usr/bin/firefox &' /etc/X11/xinit/xinitrc
 
 EXPOSE 5901