diff --git a/crates/fj-core/src/operations/insert.rs b/crates/fj-core/src/operations/insert/insert_trait.rs
similarity index 76%
rename from crates/fj-core/src/operations/insert.rs
rename to crates/fj-core/src/operations/insert/insert_trait.rs
index 2e6f382dc..cd19325c2 100644
--- a/crates/fj-core/src/operations/insert.rs
+++ b/crates/fj-core/src/operations/insert/insert_trait.rs
@@ -3,11 +3,12 @@ use crate::{
         Curve, Cycle, Face, GlobalEdge, HalfEdge, Region, Shell, Sketch, Solid,
         Surface, Vertex,
     },
+    operations::{Polygon, TetrahedronShell},
     services::Services,
     storage::Handle,
 };
 
-use super::{Polygon, TetrahedronShell};
+use super::{IsInsertedNo, IsInsertedYes};
 
 /// Insert an object into its respective store
 ///
@@ -56,33 +57,6 @@ impl_insert!(
     Vertex, vertices;
 );
 
-/// Indicate whether an object has been inserted
-///
-/// Intended to be used as a type parameter bound for structs that need to track
-/// whether their contents have been inserted or not.
-pub trait IsInserted {
-    /// The type of the object for which the insertion status is tracked
-    type T<T>;
-}
-
-/// Indicate that an object has been inserted
-///
-/// See [`IsInserted`].
-pub struct IsInsertedYes;
-
-impl IsInserted for IsInsertedYes {
-    type T<T> = Handle<T>;
-}
-
-/// Indicate that an object has not been inserted
-///
-/// See [`IsInserted`].
-pub struct IsInsertedNo;
-
-impl IsInserted for IsInsertedNo {
-    type T<T> = T;
-}
-
 impl<const D: usize> Insert for Polygon<D, IsInsertedNo> {
     type Inserted = Polygon<D, IsInsertedYes>;
 
diff --git a/crates/fj-core/src/operations/insert/is_inserted.rs b/crates/fj-core/src/operations/insert/is_inserted.rs
new file mode 100644
index 000000000..992e2f43d
--- /dev/null
+++ b/crates/fj-core/src/operations/insert/is_inserted.rs
@@ -0,0 +1,30 @@
+use std::borrow::Borrow;
+
+use crate::storage::Handle;
+
+/// Indicate whether an object has been inserted
+///
+/// Intended to be used as a type parameter bound for structs that need to track
+/// whether their contents have been inserted or not.
+pub trait IsInserted {
+    /// The type of the object for which the insertion status is tracked
+    type T<T>: Borrow<T>;
+}
+
+/// Indicate that an object has been inserted
+///
+/// See [`IsInserted`].
+pub struct IsInsertedYes;
+
+impl IsInserted for IsInsertedYes {
+    type T<T> = Handle<T>;
+}
+
+/// Indicate that an object has not been inserted
+///
+/// See [`IsInserted`].
+pub struct IsInsertedNo;
+
+impl IsInserted for IsInsertedNo {
+    type T<T> = T;
+}
diff --git a/crates/fj-core/src/operations/insert/mod.rs b/crates/fj-core/src/operations/insert/mod.rs
new file mode 100644
index 000000000..bc3815384
--- /dev/null
+++ b/crates/fj-core/src/operations/insert/mod.rs
@@ -0,0 +1,7 @@
+mod insert_trait;
+mod is_inserted;
+
+pub use self::{
+    insert_trait::Insert,
+    is_inserted::{IsInserted, IsInsertedNo, IsInsertedYes},
+};
diff --git a/crates/fj-core/src/storage/handle.rs b/crates/fj-core/src/storage/handle.rs
index 15b5f8d18..63eea2908 100644
--- a/crates/fj-core/src/storage/handle.rs
+++ b/crates/fj-core/src/storage/handle.rs
@@ -1,4 +1,6 @@
-use std::{any::type_name, cmp::Ordering, fmt, hash::Hash, ops::Deref};
+use std::{
+    any::type_name, borrow::Borrow, cmp::Ordering, fmt, hash::Hash, ops::Deref,
+};
 
 use super::{blocks::Index, store::StoreInner};
 
@@ -82,6 +84,12 @@ impl<T> Deref for Handle<T> {
     }
 }
 
+impl<T> Borrow<T> for Handle<T> {
+    fn borrow(&self) -> &T {
+        self.deref()
+    }
+}
+
 impl<T> Clone for Handle<T> {
     fn clone(&self) -> Self {
         Self {