diff --git a/fly.toml b/fly.toml
index c71b684..c1403b5 100644
--- a/fly.toml
+++ b/fly.toml
@@ -15,6 +15,7 @@ kill_timeout = 5
   # S3_ALIAS_HOST=files.example.com
 
 [mounts]
+  processes = ["rails"]
   source = "mastodon_uploads"
   destination = "/opt/mastodon/public/system"