diff --git a/docker-compose.yml b/docker-compose.yml
index 2485743f..ee029a23 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -4587,7 +4587,7 @@ services:
     environment:
       POSTGRES_USER: synapse
       POSTGRES_PASSWORD: ${SYNAPSE_POSTGRES_PASSWORD}
-      POSTGRES_DB: synapse
+      POSTGRES_INITDB_ARGS: "--encoding=UTF-8 --lc-collate=C --lc-ctype=C"
     expose:
       - 5432
     restart: unless-stopped