diff --git a/proxmox/install-in-ct.sh b/proxmox/install-in-ct.sh
index 729c85a..89a8399 100644
--- a/proxmox/install-in-ct.sh
+++ b/proxmox/install-in-ct.sh
@@ -20,9 +20,22 @@ SKIP_FETCH="${SKIP_FETCH:-0}"
 
 export DEBIAN_FRONTEND=noninteractive
 export API_DIR
+# Avoid perl locale warnings in minimal LXC (host may export unsupported LC_*).
+export LANG=C.UTF-8
+export LC_ALL=C.UTF-8
+unset LANGUAGE LC_TIME LC_MESSAGES 2>/dev/null || true
 
 msg() { echo -e " ==> $*"; }
 
+as_postgres() {
+  # Script runs as root in CT; sudo is not installed.
+  if command -v runuser >/dev/null 2>&1; then
+    runuser -u postgres -- "$@"
+  else
+    su -s /bin/bash postgres -c "$*"
+  fi
+}
+
 detect_public_url() {
   if [[ -n "$PUBLIC_URL" ]]; then
     PUBLIC_URL=$(echo "$PUBLIC_URL" | sed 's:/*$::')
@@ -43,7 +56,10 @@ detect_public_url() {
 install_base() {
   msg "Installing base packages"
   apt-get update -y
-  apt-get install -y ca-certificates curl gnupg postgresql postgresql-contrib
+  apt-get install -y ca-certificates curl gnupg locales postgresql postgresql-contrib
+  sed -i 's/^# *en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen 2>/dev/null || true
+  locale-gen en_US.UTF-8 >/dev/null 2>&1 || true
+  update-locale LANG=en_US.UTF-8 >/dev/null 2>&1 || true
 }
 
 install_aspnet_runtime() {
@@ -61,16 +77,16 @@ install_aspnet_runtime() {
 setup_postgres() {
   msg "Configuring PostgreSQL"
   systemctl enable --now postgresql
-  if ! sudo -u postgres psql -tAc "SELECT 1 FROM pg_roles WHERE rolname='${PG_USER}'" | grep -q 1; then
-    sudo -u postgres psql -c "CREATE USER ${PG_USER} WITH PASSWORD '${PG_PASS}';"
+  if ! as_postgres psql -tAc "SELECT 1 FROM pg_roles WHERE rolname='${PG_USER}'" | grep -q 1; then
+    as_postgres psql -c "CREATE USER ${PG_USER} WITH PASSWORD '${PG_PASS}';"
   else
-    sudo -u postgres psql -c "ALTER USER ${PG_USER} WITH PASSWORD '${PG_PASS}';"
+    as_postgres psql -c "ALTER USER ${PG_USER} WITH PASSWORD '${PG_PASS}';"
   fi
-  if ! sudo -u postgres psql -tAc "SELECT 1 FROM pg_database WHERE datname='${PG_DB}'" | grep -q 1; then
-    sudo -u postgres psql -c "CREATE DATABASE ${PG_DB} OWNER ${PG_USER};"
+  if ! as_postgres psql -tAc "SELECT 1 FROM pg_database WHERE datname='${PG_DB}'" | grep -q 1; then
+    as_postgres psql -c "CREATE DATABASE ${PG_DB} OWNER ${PG_USER};"
   fi
-  sudo -u postgres psql -c "GRANT ALL PRIVILEGES ON DATABASE ${PG_DB} TO ${PG_USER};"
-  sudo -u postgres psql -d "$PG_DB" -c "GRANT ALL ON SCHEMA public TO ${PG_USER};" || true
+  as_postgres psql -c "GRANT ALL PRIVILEGES ON DATABASE ${PG_DB} TO ${PG_USER};"
+  as_postgres psql -d "$PG_DB" -c "GRANT ALL ON SCHEMA public TO ${PG_USER};" || true
   msg "PostgreSQL ready (db/user/pass=${PG_DB})"
 }