diff --git a/Dockerfile b/Dockerfile
index 168946794..35f530518 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,7 +10,7 @@ ENV HOME /root
 RUN  add-apt-repository ppa:nginx/development
 
 # Install system packages
-RUN apt-get update && apt-get upgrade # 22FEB2017
+RUN apt-get update && apt-get upgrade -y # 22FEB2017
 RUN apt-get install -y \
      g++               \
      gdb               \