diff --git a/docker/Dockerfile b/docker/Dockerfile
index 394f050a..148bc973 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,5 +1,9 @@
 FROM ubuntu:latest
 
+# Set the locale
+RUN locale-gen en_US.UTF-8
+ENV LANG='en_US.UTF-8' LANGUAGE='en_US:en' LC_ALL='en_US.UTF-8'
+
 # Combine all apt-get install commands or Docker will attempt to use cache
 RUN apt-get update && apt-get install -y \
         autoconf \
@@ -21,7 +25,7 @@ RUN gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A170311380
 RUN \curl -sSL https://get.rvm.io | bash -s stable
 
 RUN /bin/bash -l -c "rvm requirements"
-RUN /bin/bash -l -c "rvm install 2.2.0"
+RUN /bin/bash -l -c "rvm install 2.3.3"
 RUN /bin/bash -l -c "gem install rake --no-ri --no-rdoc"
 
 RUN /bin/bash -l -c "curl -Lo- https://bit.ly/janus-bootstrap | bash"