diff --git a/build_library/build_image_util.sh b/build_library/build_image_util.sh
index 009859a712..04229593b8 100755
--- a/build_library/build_image_util.sh
+++ b/build_library/build_image_util.sh
@@ -112,6 +112,27 @@ run_ldconfig() {
   esac
 }
 
+run_localedef() {
+  local root_fs_dir="$1" loader=()
+  case ${ARCH} in
+  arm64)
+    loader=( qemu-aarch64 -L "${root_fs_dir}" );;
+  amd64)
+    loader=( "${root_fs_dir}/usr/lib64/ld-linux-x86-64.so.2" \
+               --library-path "${root_fs_dir}/usr/lib64" );;
+  *)
+    die "Unable to run localedev for ARCH ${ARCH}";;
+  esac
+  info "Generating C.UTF-8 locale..."
+  local i18n="${root_fs_dir}/usr/share/i18n"
+  # localedef will silently fall back to /usr/share/i18n if missing so
+  # check that the paths we want are available first.
+  [[ -f "${i18n}/charmaps/UTF-8.gz" ]] || die
+  [[ -f "${i18n}/locales/C" ]] || die
+  sudo I18NPATH="${i18n}" "${loader[@]}" "${root_fs_dir}/usr/bin/localedef" \
+      --prefix="${root_fs_dir}" --charmap=UTF-8 --inputfile=C C.UTF-8
+}
+
 # Basic command to emerge binary packages into the target image.
 # Arguments to this command are passed as addition options/arguments
 # to the basic emerge command.
diff --git a/build_library/dev_image_util.sh b/build_library/dev_image_util.sh
index 38a28edfb4..1be288b5a2 100755
--- a/build_library/dev_image_util.sh
+++ b/build_library/dev_image_util.sh
@@ -97,6 +97,7 @@ create_dev_image() {
   set_image_profile dev
   emerge_to_image "${root_fs_dir}" @system ${base_pkg}
   run_ldconfig "${root_fs_dir}"
+  run_localedef "${root_fs_dir}"
   write_packages "${root_fs_dir}" "${BUILD_DIR}/${image_packages}"
   write_licenses "${root_fs_dir}" "${BUILD_DIR}/${image_licenses}"
 
diff --git a/build_library/prod_image_util.sh b/build_library/prod_image_util.sh
index 1c0611fdbf..d53fde10a3 100755
--- a/build_library/prod_image_util.sh
+++ b/build_library/prod_image_util.sh
@@ -76,6 +76,7 @@ create_prod_image() {
   extract_prod_gcc "${root_fs_dir}"
   emerge_to_image "${root_fs_dir}" "${base_pkg}"
   run_ldconfig "${root_fs_dir}"
+  run_localedef "${root_fs_dir}"
   write_packages "${root_fs_dir}" "${BUILD_DIR}/${image_packages}"
   write_licenses "${root_fs_dir}" "${BUILD_DIR}/${image_licenses}"
   extract_docs "${root_fs_dir}"
@@ -113,6 +114,9 @@ EOF
   sudo mv -n ${root_fs_dir}/etc/pam.d/* ${root_fs_dir}/usr/lib/pam.d/
   sudo rmdir ${root_fs_dir}/etc/pam.d
 
+  # Remove source locale data, only need to ship the compiled archive.
+  sudo rm -rf ${root_fs_dir}/usr/share/i18n/
+
   finish_image \
       "${image_name}" \
       "${disk_layout}" \