diff --git a/utils/copy_type.ts b/utils/copy_type.ts
index c2780e972..b476d8042 100644
--- a/utils/copy_type.ts
+++ b/utils/copy_type.ts
@@ -101,3 +101,48 @@ writeFile("node_modules\\@jscad\\modeling\\src\\operations\\modifiers\\retessell
             console.log("retessellate.d.ts ok");
     }
 );
+
+
+writeFile("node_modules/@jscad/modeling/src/operations/booleans/trees/splitPolygonByPlane.d.ts", `
+import { Poly3 } from '../../../geometries/types';
+import { Plane } from '../../../maths/types';
+
+enum ResType
+{
+    coplanar_front = 0,
+    coplanar_back = 1,
+    front = 2,
+    back = 3,
+    spanning = 4,
+}
+
+
+interface SplitRes
+{
+    type: ResType,
+    front: Poly3,
+    back: Poly3;
+}
+
+// Returns object:
+// .type:
+//   0: coplanar-front
+//   1: coplanar-back
+//   2: front
+//   3: back
+//   4: spanning
+// In case the polygon is spanning, returns:
+// .front: a Polygon3 of the front part
+// .back: a Polygon3 of the back part
+declare function splitPolygonByPlane(plane: Plane, polygon: Poly3): SplitRes;
+
+export default splitPolygonByPlane;`, err => { });
+
+writeFile("node_modules/@jscad/modeling/src/operations/booleans/scission.d.ts", `
+iimport { Geom2, Geom3 } from '../../geometries/types'
+import RecursiveArray from '../../utils/recursiveArray'
+
+export default scission
+
+declare function scission(...geometries: RecursiveArray<Geom2>): Geom2
+declare function scission(...geometries: RecursiveArray<Geom3>): Geom3`, err => { });