diff --git a/scripts/deploy-prod.sh b/scripts/deploy-prod.sh
index 89d034a..cb85c6c 100755
--- a/scripts/deploy-prod.sh
+++ b/scripts/deploy-prod.sh
@@ -133,6 +133,9 @@ cd "$ROOT"
 
 if [ -f "$ROOT/.env.docker" ]; then
   sed -i 's/\r$//' "$ROOT/.env.docker"
+  # Docker Compose reads .env (not .env.docker) for ${...} interpolation.
+  # Sync .env from .env.docker so POSTGRES_PASSWORD etc. are interpolated correctly.
+  grep -v '???' "$ROOT/.env.docker" | grep -v '^#' > "$ROOT/.env"
 fi
 
 load_env_docker