diff --git a/config/settings.yml b/config/settings.yml
index 255d8b9a7..9a82fbf96 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -165,7 +165,7 @@ memcached-local:
   maximum-weight: 104857600 # 100MiB
 
 upload-cache:
-  host: "_env:UPLOAD_S3_HOST:localhost"
+  host: "_env:UPLOAD_S3_HOST:" # should be optional, but all file transfers will be empty without an S3 cache
   port: "_env:UPLOAD_S3_PORT:9000"
   access-key: "_env:UPLOAD_S3_KEY_ID:"
   secret-key: "_env:UPLOAD_S3_KEY"