diff --git a/docker-compose.yml b/docker-compose.yml
index 1db95db..e706f44 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -7,6 +7,7 @@ services:
       POSTGRES_DB: ${POSTGRES_DB:-synapse}
       POSTGRES_USER: ${POSTGRES_USER:-synapse}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?POSTGRES_PASSWORD is required}
+      POSTGRES_INITDB_ARGS: "--encoding=UTF8 --locale=C"
     volumes:
       - /opt/swchat/data/postgres:/var/lib/postgresql/data
     networks: