diff --git a/docker/single-process/scripts/prepare b/docker/single-process/scripts/prepare
index aa0c40ba..81079e43 100755
--- a/docker/single-process/scripts/prepare
+++ b/docker/single-process/scripts/prepare
@@ -13,11 +13,6 @@ path-exclude=/usr/share/doc/*
 path-include=/usr/share/doc/*/copyright
 EOF
 
-cat > /etc/default/locale <<EOF
-LC_ALL=en_US.UTF-8
-LANG=en_US.UTF-8
-EOF
-
 export LC_ALL=C
 export DEBIAN_FRONTEND=noninteractive
 minimal_apt_get_install='apt-get install -y --no-install-recommends'
@@ -33,6 +28,8 @@ $minimal_apt_get_install build-essential checkinstall git-core \
   graphviz libgraphviz-dev \
   libmysqlclient-dev libpq-dev libsqlite3-dev \
   ruby2.2 ruby2.2-dev
+locale-gen en_US.UTF-8
+update-locale LANG=en_US.UTF-8 LC_CTYPE=en_US.UTF-8
 gem install --no-ri --no-rdoc bundler
 
 apt-get purge -y python3* rsyslog rsync manpages
diff --git a/docker/single-process/scripts/setup b/docker/single-process/scripts/setup
index 621af432..348041e7 100755
--- a/docker/single-process/scripts/setup
+++ b/docker/single-process/scripts/setup
@@ -18,6 +18,8 @@ cd app
 sudo -u huginn -H mkdir -p tmp/pids tmp/cache tmp/sockets log
 chmod -R u+rwX log tmp
 
+export LC_ALL=en_US.UTF-8
+
 # HACK: We need a database connection to precompile the assets, use sqlite for that
 echo "gem 'sqlite3', '~> 1.3.11'" >> Gemfile
 sudo -u huginn -H RAILS_ENV=production APP_SECRET_TOKEN=secret DATABASE_ADAPTER=sqlite3 ON_HEROKU=true bundle install --without test development --path vendor/bundle -j 4