diff --git a/crates/fj-core/src/operations/join/cycle.rs b/crates/fj-core/src/operations/join/cycle.rs
index f4e61b6ec..45122513b 100644
--- a/crates/fj-core/src/operations/join/cycle.rs
+++ b/crates/fj-core/src/operations/join/cycle.rs
@@ -3,7 +3,7 @@ use std::ops::RangeInclusive;
 use itertools::Itertools;
 
 use crate::{
-    geometry::HalfEdgeGeom,
+    geometry::{HalfEdgeGeom, LocalCurveGeom},
     operations::{
         build::BuildHalfEdge,
         geometry::UpdateHalfEdgeGeometry,
@@ -92,7 +92,7 @@ impl JoinCycle for Cycle {
     fn add_joined_edges<Es>(
         &self,
         edges: Es,
-        _: Handle<Surface>,
+        surface: Handle<Surface>,
         core: &mut Core,
     ) -> Self
     where
@@ -103,14 +103,24 @@ impl JoinCycle for Cycle {
             .into_iter()
             .circular_tuple_windows()
             .map(|((prev_half_edge, _), (half_edge, geometry))| {
-                HalfEdge::unjoined(core)
+                let half_edge = HalfEdge::unjoined(core)
                     .update_curve(|_, _| half_edge.curve().clone(), core)
                     .update_start_vertex(
                         |_, _| prev_half_edge.start_vertex().clone(),
                         core,
                     )
                     .insert(core)
-                    .set_geometry(geometry, &mut core.layers.geometry)
+                    .set_geometry(geometry, &mut core.layers.geometry);
+
+                core.layers.geometry.define_curve(
+                    half_edge.curve().clone(),
+                    surface.clone(),
+                    LocalCurveGeom {
+                        path: geometry.path,
+                    },
+                );
+
+                half_edge
             })
             .collect::<Vec<_>>();
         self.add_half_edges(half_edges, core)