diff --git a/dpppt-config-backend/src/main/java/org/dpppt/switzerland/backend/sdk/config/ws/config/WSBaseConfig.java b/dpppt-config-backend/src/main/java/org/dpppt/switzerland/backend/sdk/config/ws/config/WSBaseConfig.java
index 4a4bc99..512a9ad 100644
--- a/dpppt-config-backend/src/main/java/org/dpppt/switzerland/backend/sdk/config/ws/config/WSBaseConfig.java
+++ b/dpppt-config-backend/src/main/java/org/dpppt/switzerland/backend/sdk/config/ws/config/WSBaseConfig.java
@@ -145,6 +145,8 @@ public MessageSource messageSource() {
 
         messageSource.setBasename("classpath:i18n/messages");
         messageSource.setDefaultEncoding("UTF-8");
+        messageSource.setFallbackToSystemLocale(false);
+        messageSource.setDefaultLocale(null);
         return messageSource;
     }