diff --git a/src/c3py/poset.py b/src/c3py/poset.py
index 69fcca7..4b4c9e5 100644
--- a/src/c3py/poset.py
+++ b/src/c3py/poset.py
@@ -20,7 +20,8 @@ def __eq__(self, __value: object) -> bool:
         return self == __value
 
     def __hash__(self) -> int:
-        return hash(nx.weisfeiler_lehman_graph_hash(self.G))
+        # for our purposes, we only care about the set of edges
+        return hash(frozenset(self.G.edges))
 
     def link(self, a: str, b: str):
         self.G.add_edge(a, b)