diff --git a/src/algorithms.rs b/src/algorithms.rs
index 01a6c31..10736bb 100644
--- a/src/algorithms.rs
+++ b/src/algorithms.rs
@@ -27,6 +27,7 @@ pub struct DijkstraResult<V: Copy> {
     pub predecessors: VertexMap<V, Option<V>>,
 }
 
+// TODO: Generalize the return type of the weight function.
 pub fn dijkstra<G, W>(graph: &G, source: G::Vertex, weight: W) -> DijkstraResult<G::Vertex>
 where
     G: GraphTopology,