diff --git a/bumble/device.py b/bumble/device.py
index 57ecc766..b01dc58b 100644
--- a/bumble/device.py
+++ b/bumble/device.py
@@ -1186,8 +1186,8 @@ class Device(CompositeEventEmitter):
     def create_l2cap_registrar(self, psm):
         return lambda handler: self.register_l2cap_server(psm, handler)
 
-    def register_l2cap_server(self, psm, server):
-        self.l2cap_channel_manager.register_server(psm, server)
+    def register_l2cap_server(self, psm, server) -> int:
+        return self.l2cap_channel_manager.register_server(psm, server)
 
     def register_l2cap_channel_server(
         self,