diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 28f913e57..9e668e0ba 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -14,7 +14,7 @@ variables:
   POSTGRES_DB: uniworx_test
   POSTGRES_USER: uniworx
   POSTGRES_PASSWORD: uniworx
-  POSTGRES_INITDB_ARGS: "--locale=de-DE --encoding=UTF-8"
+  POSTGRES_INITDB_ARGS: "--locale=de_DE --encoding=UTF-8"
   TZ: Europe/Berlin
 
 stages: