diff --git a/Dockerfile b/Dockerfile
index 8674ab8..d0abd37 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,11 +3,11 @@ MAINTAINER Tobe O <thosakwe@gmail.com>
 
 # Install Dart SDK 1.21
 RUN sudo apt-get update
-RUN sudo apt-get install apt-transport-https
+RUN sudo apt-get install -y apt-transport-https
 RUN sudo sh -c 'curl https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -'
 RUN sudo sh -c 'curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_stable.list > /etc/apt/sources.list.d/dart_stable.list'
 RUN sudo apt-get update
-RUN sudo apt-get install dart=1.21.*
+RUN sudo apt-get install -y dart=1.21.*
 RUN export PATH="/usr/lib/dart/bin:$PATH"
 
 # Copy necessary files