diff --git a/src/c3nav/routing/router.py b/src/c3nav/routing/router.py
index 1a899b31..cc8ca9a3 100644
--- a/src/c3nav/routing/router.py
+++ b/src/c3nav/routing/router.py
@@ -587,7 +587,7 @@ RouterProxiedType = TypeVar('RouterProxiedType')
 class BaseRouterProxy(Generic[RouterProxiedType]):
     src: RouterProxiedType
     nodes: set[int] = field(default_factory=set)
-    nodes_addition: NodeConnectionsByNode = field(default_factory=set)
+    nodes_addition: NodeConnectionsByNode = field(default_factory=dict)
 
     @cached_property
     def geometry_prep(self):