diff --git a/services/tunnelbroker/build.rs b/services/tunnelbroker/build.rs
--- a/services/tunnelbroker/build.rs
+++ b/services/tunnelbroker/build.rs
@@ -26,7 +26,7 @@
   add_import_path("src/libcpp/src/DeliveryBroker");
   add_import_path("src/libcpp/src/Tools");
 
-  cxx_build::bridge("src/main.rs")
+  cxx_build::bridge("src/cxx_bridge.rs")
     .files(get_cpp_sources("../lib/src"))
     .files(get_cpp_sources("src/libcpp/src"))
     .file(Path::new("src/libcpp/Tunnelbroker.cpp"))
diff --git a/services/tunnelbroker/src/cxx_bridge.rs b/services/tunnelbroker/src/cxx_bridge.rs
new file mode 100644
--- /dev/null
+++ b/services/tunnelbroker/src/cxx_bridge.rs
@@ -0,0 +1,7 @@
+#[cxx::bridge]
+pub mod ffi {
+  unsafe extern "C++" {
+    include!("tunnelbroker/src/libcpp/Tunnelbroker.h");
+    pub fn initialization();
+  }
+}
diff --git a/services/tunnelbroker/src/main.rs b/services/tunnelbroker/src/main.rs
--- a/services/tunnelbroker/src/main.rs
+++ b/services/tunnelbroker/src/main.rs
@@ -1,16 +1,9 @@
+pub mod cxx_bridge;
 pub mod server;
 
-#[cxx::bridge]
-mod ffi {
-  unsafe extern "C++" {
-    include!("tunnelbroker/src/libcpp/Tunnelbroker.h");
-    pub fn initialization();
-  }
-}
-
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
-  ffi::initialization();
+  cxx_bridge::ffi::initialization();
   server::run_grpc_server().await?;
 
   Ok(())