diff --git a/src/maasserver/preseed_network.py b/src/maasserver/preseed_network.py
index bb56765..1185ff1 100644
--- a/src/maasserver/preseed_network.py
+++ b/src/maasserver/preseed_network.py
@@ -203,7 +203,7 @@ class InterfaceConfiguration:
         return {
             route
             for route in self.routes
-            if route.source == source
+            if str(route.source.cidr) == str(source.cidr)
         }

     def _generate_addresses(self, version=1):