diff --git a/gufe/network.py b/gufe/network.py
index e2b21ec8..79a56f7a 100644
--- a/gufe/network.py
+++ b/gufe/network.py
@@ -11,7 +11,6 @@
 from .transformations import Transformation
 
 
-
 class AlchemicalNetwork(GufeTokenizable):
     _edges: frozenset[Transformation]
     _nodes: frozenset[ChemicalSystem]
@@ -118,7 +117,7 @@ def to_graphml(self) -> str:
         raise NotImplementedError
 
     @classmethod
-    def from_graphml(cls, str):
+    def from_graphml(cls, str) -> Self:
         """Currently not implemented"""
         raise NotImplementedError