diff --git a/crates/fj-kernel/src/operations/build/cycle.rs b/crates/fj-kernel/src/operations/build/cycle.rs
index ffb76f516..2e97cf50d 100644
--- a/crates/fj-kernel/src/operations/build/cycle.rs
+++ b/crates/fj-kernel/src/operations/build/cycle.rs
@@ -3,12 +3,10 @@ use itertools::Itertools;
 
 use crate::{
     objects::{Cycle, HalfEdge},
-    operations::Insert,
+    operations::{BuildHalfEdge, Insert},
     services::Services,
 };
 
-use super::BuildHalfEdge;
-
 /// Build a [`Cycle`]
 pub trait BuildCycle {
     /// Build an empty cycle
diff --git a/crates/fj-kernel/src/operations/build/face.rs b/crates/fj-kernel/src/operations/build/face.rs
index 76e12f18d..4146367a2 100644
--- a/crates/fj-kernel/src/operations/build/face.rs
+++ b/crates/fj-kernel/src/operations/build/face.rs
@@ -3,13 +3,14 @@ use fj_math::Point;
 
 use crate::{
     objects::{Cycle, Face, HalfEdge, Surface, Vertex},
-    operations::{Insert, IsInserted, IsInsertedNo},
+    operations::{
+        BuildCycle, BuildHalfEdge, BuildSurface, Insert, IsInserted,
+        IsInsertedNo,
+    },
     services::Services,
     storage::Handle,
 };
 
-use super::{BuildCycle, BuildHalfEdge, BuildSurface};
-
 /// Build a [`Face`]
 pub trait BuildFace {
     /// Build a face with an empty exterior, no interiors, and no color
diff --git a/crates/fj-kernel/src/operations/build/mod.rs b/crates/fj-kernel/src/operations/build/mod.rs
index fe6010c3b..273ea0fee 100644
--- a/crates/fj-kernel/src/operations/build/mod.rs
+++ b/crates/fj-kernel/src/operations/build/mod.rs
@@ -1,15 +1,6 @@
-mod cycle;
-mod edge;
-mod face;
-mod shell;
-mod solid;
-mod surface;
-
-pub use self::{
-    cycle::BuildCycle,
-    edge::BuildHalfEdge,
-    face::{BuildFace, Polygon},
-    shell::{BuildShell, TetrahedronShell},
-    solid::{BuildSolid, Tetrahedron},
-    surface::BuildSurface,
-};
+pub mod cycle;
+pub mod edge;
+pub mod face;
+pub mod shell;
+pub mod solid;
+pub mod surface;
diff --git a/crates/fj-kernel/src/operations/build/shell.rs b/crates/fj-kernel/src/operations/build/shell.rs
index 41ed095af..83aeed52e 100644
--- a/crates/fj-kernel/src/operations/build/shell.rs
+++ b/crates/fj-kernel/src/operations/build/shell.rs
@@ -3,13 +3,12 @@ use fj_math::Point;
 use crate::{
     objects::{Face, Shell},
     operations::{
-        Insert, IsInserted, IsInsertedNo, IsInsertedYes, JoinCycle, UpdateFace,
+        BuildFace, Insert, IsInserted, IsInsertedNo, IsInsertedYes, JoinCycle,
+        Polygon, UpdateFace,
     },
     services::Services,
 };
 
-use super::{BuildFace, Polygon};
-
 /// Build a [`Shell`]
 pub trait BuildShell {
     /// Build a tetrahedron from the provided points
diff --git a/crates/fj-kernel/src/operations/join/mod.rs b/crates/fj-kernel/src/operations/join/mod.rs
index 9594ced45..a7b6b03b5 100644
--- a/crates/fj-kernel/src/operations/join/mod.rs
+++ b/crates/fj-kernel/src/operations/join/mod.rs
@@ -1,3 +1 @@
-mod cycle;
-
-pub use self::cycle::JoinCycle;
+pub mod cycle;
diff --git a/crates/fj-kernel/src/operations/mod.rs b/crates/fj-kernel/src/operations/mod.rs
index 313bdeaae..5cff834e4 100644
--- a/crates/fj-kernel/src/operations/mod.rs
+++ b/crates/fj-kernel/src/operations/mod.rs
@@ -7,12 +7,17 @@ mod update;
 
 pub use self::{
     build::{
-        BuildCycle, BuildFace, BuildHalfEdge, BuildShell, BuildSolid,
-        BuildSurface, Polygon, Tetrahedron, TetrahedronShell,
+        cycle::BuildCycle,
+        edge::BuildHalfEdge,
+        face::{BuildFace, Polygon},
+        shell::{BuildShell, TetrahedronShell},
+        solid::{BuildSolid, Tetrahedron},
+        surface::BuildSurface,
     },
     insert::{Insert, IsInserted, IsInsertedNo, IsInsertedYes},
-    join::JoinCycle,
+    join::cycle::JoinCycle,
     update::{
-        UpdateCycle, UpdateFace, UpdateHalfEdge, UpdateShell, UpdateSolid,
+        cycle::UpdateCycle, edge::UpdateHalfEdge, face::UpdateFace,
+        shell::UpdateShell, solid::UpdateSolid,
     },
 };
diff --git a/crates/fj-kernel/src/operations/update/mod.rs b/crates/fj-kernel/src/operations/update/mod.rs
index 431b97368..85f65f886 100644
--- a/crates/fj-kernel/src/operations/update/mod.rs
+++ b/crates/fj-kernel/src/operations/update/mod.rs
@@ -1,10 +1,5 @@
-mod cycle;
-mod edge;
-mod face;
-mod shell;
-mod solid;
-
-pub use self::{
-    cycle::UpdateCycle, edge::UpdateHalfEdge, face::UpdateFace,
-    shell::UpdateShell, solid::UpdateSolid,
-};
+pub mod cycle;
+pub mod edge;
+pub mod face;
+pub mod shell;
+pub mod solid;
diff --git a/crates/fj-kernel/src/operations/update/shell.rs b/crates/fj-kernel/src/operations/update/shell.rs
index f8717e666..3133b2d83 100644
--- a/crates/fj-kernel/src/operations/update/shell.rs
+++ b/crates/fj-kernel/src/operations/update/shell.rs
@@ -6,10 +6,10 @@ use crate::{
 /// Update a [`Shell`]
 pub trait UpdateShell {
     /// Update a face of the shell
-    fn update_face(
+    fn replace_face(
         &self,
-        handle: &Handle<Face>,
-        f: impl FnMut(&Handle<Face>) -> Handle<Face>,
+        original: &Handle<Face>,
+        replacement: Handle<Face>,
     ) -> Shell;
 
     /// Remove a face from the shell
@@ -17,14 +17,14 @@ pub trait UpdateShell {
 }
 
 impl UpdateShell for Shell {
-    fn update_face(
+    fn replace_face(
         &self,
-        handle: &Handle<Face>,
-        mut f: impl FnMut(&Handle<Face>) -> Handle<Face>,
+        original: &Handle<Face>,
+        replacement: Handle<Face>,
     ) -> Shell {
         let faces = self.faces().into_iter().map(|face| {
-            if face.id() == handle.id() {
-                f(face)
+            if face.id() == original.id() {
+                replacement.clone()
             } else {
                 face.clone()
             }
diff --git a/crates/fj-kernel/src/validate/shell.rs b/crates/fj-kernel/src/validate/shell.rs
index 91915bc3e..f1a81b4e8 100644
--- a/crates/fj-kernel/src/validate/shell.rs
+++ b/crates/fj-kernel/src/validate/shell.rs
@@ -210,20 +210,24 @@ mod tests {
             [[0., 0., 0.], [0., 1., 0.], [1., 0., 0.], [0., 0., 1.]],
             &mut services,
         );
-        let invalid = valid.shell.update_face(&valid.abc.face, |face| {
-            face.update_exterior(|cycle| {
-                cycle
-                    .update_nth_half_edge(0, |half_edge| {
-                        let global_form =
-                            GlobalEdge::new().insert(&mut services);
-                        half_edge
-                            .replace_global_form(global_form)
-                            .insert(&mut services)
-                    })
-                    .insert(&mut services)
-            })
-            .insert(&mut services)
-        });
+        let invalid = valid.shell.replace_face(
+            &valid.abc.face,
+            valid
+                .abc
+                .face
+                .update_exterior(|cycle| {
+                    cycle
+                        .update_nth_half_edge(0, |half_edge| {
+                            let global_form =
+                                GlobalEdge::new().insert(&mut services);
+                            half_edge
+                                .replace_global_form(global_form)
+                                .insert(&mut services)
+                        })
+                        .insert(&mut services)
+                })
+                .insert(&mut services),
+        );
 
         valid.shell.validate_and_return_first_error()?;
         assert_contains_err!(