diff --git a/crates/fj-core/src/geometry/surface.rs b/crates/fj-core/src/geometry/surface.rs
index 8dd64fd57..50aed0332 100644
--- a/crates/fj-core/src/geometry/surface.rs
+++ b/crates/fj-core/src/geometry/surface.rs
@@ -65,7 +65,7 @@ impl SurfaceGeom {
 
         let [a, b] = self
             .u
-            .line_segment_at(Point::from([point_surface.u]), tolerance)
+            .line_segment_at(Point::from([point_surface.u]), tolerance.into())
             .map(|point_global| point_global + self.v * point_surface.v);
 
         let c = a + (b - a) / 2.;