diff --git a/docs/guides/useful-commands.md b/docs/guides/useful-commands.md
index def6138..237dde0 100644
--- a/docs/guides/useful-commands.md
+++ b/docs/guides/useful-commands.md
@@ -44,3 +44,18 @@ docker exec -it remnanode tail -n +1 -f /var/log/supervisor/xray.err.log
 ```bash
 cd /opt/remnanode && docker compose down && docker compose up -d && docker compose logs -f -t
 ```
+
+### FIX postgres REFRESH COLLATION VERSION
+
+```bash
+cd /opt/remnawave && docker compose exec remnawave-db psql -U $(grep '^POSTGRES_USER=' .env | cut -d '=' -f2) -d remnawave_db -c "
+DO \$\$
+DECLARE
+    db_name text;
+BEGIN
+    FOR db_name IN SELECT datname FROM pg_database WHERE datname NOT IN ('template0') LOOP
+        EXECUTE format('ALTER DATABASE %I REFRESH COLLATION VERSION', db_name);
+    END LOOP;
+END \$\$;
+"
+```