diff --git a/Dockerfile-dev b/Dockerfile-dev
index c1dce09fe1..04210986fe 100644
--- a/Dockerfile-dev
+++ b/Dockerfile-dev
@@ -4,7 +4,7 @@ EXPOSE 9991
 
 RUN apt-get update && apt-get install -y wget
 
-RUN locale-gen en_US.UTF-8
+RUN localedef -i en_US -f UTF-8 en_US.UTF-8
 
 RUN useradd -d /home/zulip -m zulip && echo 'zulip ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
 
diff --git a/scripts/lib/install b/scripts/lib/install
index 36fb3b13e2..957a4635e5 100755
--- a/scripts/lib/install
+++ b/scripts/lib/install
@@ -73,7 +73,7 @@ set -x
 ZULIP_PATH="$(readlink -f $(dirname $0)/../..)"
 
 # Force a known locale.  Some packages on PyPI fail to install in some locales.
-locale-gen en_US.UTF-8
+localedef -i en_US -f UTF-8 en_US.UTF-8
 export LC_ALL="en_US.UTF-8"
 export LANG="en_US.UTF-8"
 export LANGUAGE="en_US.UTF-8"