diff --git a/src/domain.rs b/src/domain.rs
new file mode 100644
index 0000000..8f37567
--- /dev/null
+++ b/src/domain.rs
@@ -0,0 +1 @@
+pub struct SubscriberName(String);
diff --git a/src/lib.rs b/src/lib.rs
index 5d8e21e..19fce70 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,5 @@
-#![allow(clippy::toplevel_ref_arg)]
 pub mod configuration;
+pub mod domain;
 pub mod routes;
 pub mod startup;
 pub mod telemetry;