diff --git a/experiments/2025-03-18/src/geometry/sketch.rs b/experiments/2025-03-18/src/geometry/sketch.rs
index 14db59424..5aaf4bee7 100644
--- a/experiments/2025-03-18/src/geometry/sketch.rs
+++ b/experiments/2025-03-18/src/geometry/sketch.rs
@@ -67,7 +67,7 @@ impl SketchSegment {
 }
 
 struct VerticesFromSegments {
-    vertices: Vec<Handle<Vertex>>,
+    vertices: Vec<(SketchSegment, Handle<Vertex>)>,
     coincident_vertices: BTreeSet<Handle<Vertex>>,
 }
 
@@ -91,7 +91,7 @@ impl VerticesFromSegments {
                     .or_default()
                     .push(vertex.clone());
 
-                vertex
+                (segment, vertex)
             })
             .collect::<Vec<_>>();
 
@@ -109,7 +109,7 @@ impl VerticesFromSegments {
 
     fn iter(&self) -> impl Iterator<Item = ([Handle<Vertex>; 2], bool)> {
         self.vertices.iter().cloned().circular_tuple_windows().map(
-            |(start, end)| {
+            |((_, start), (_, end))| {
                 let [start_is_coincident, end_is_coincident] = [&start, &end]
                     .map(|vertex| self.coincident_vertices.contains(vertex));
                 let is_internal = start_is_coincident && end_is_coincident;