diff --git a/package-lock.json b/package-lock.json
index be224ad..2095700 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,21 +1,21 @@
 {
   "name": "@doodle3d/doodle3d-slicer",
-  "version": "0.0.4",
+  "version": "0.0.12",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
     "@doodle3d/clipper-js": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/@doodle3d/clipper-js/-/clipper-js-1.0.3.tgz",
-      "integrity": "sha512-CM0g8ALJJoTaYh6WWwQVt1ak85vvDd1YvmAFzJ1Qe8l5q84+Bbq2XYUNVCnJ5D3FJgyKDx7TOmOTe4XySClycg==",
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/@doodle3d/clipper-js/-/clipper-js-1.0.7.tgz",
+      "integrity": "sha512-8Ji8rrFWZ7LAEpIp1SQZJgewxt0FUBFeDku+ZRIR5PS0Jc6Abbq5KykQLVh1zOh3oqX2Cgl+myhqMhFeZXqutA==",
       "requires": {
-        "@doodle3d/clipper-lib": "6.2.2"
+        "@doodle3d/clipper-lib": "6.4.2-b"
       }
     },
     "@doodle3d/clipper-lib": {
-      "version": "6.2.2",
-      "resolved": "https://registry.npmjs.org/@doodle3d/clipper-lib/-/clipper-lib-6.2.2.tgz",
-      "integrity": "sha512-RLwCRi98bX4P3QcbznEFL9tLAXX32ychi+JIeS6S0BmPMvI0uSEw+IpbmihR44bqY+SxkQigs9Gcz7hMiZS2zA=="
+      "version": "6.4.2-b",
+      "resolved": "https://registry.npmjs.org/@doodle3d/clipper-lib/-/clipper-lib-6.4.2-b.tgz",
+      "integrity": "sha512-glELSijsD9b+/0d9iOdasBwqH3s+xPxD59tJ7aXkBx7klugygGOMXn7PB05AdhVyA1OYMj7GUCegaQa7nvLtmQ=="
     },
     "ansi-regex": {
       "version": "2.1.1",
diff --git a/package.json b/package.json
index f58fe60..f24a937 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@doodle3d/doodle3d-slicer",
-  "version": "0.0.4",
+  "version": "0.0.12",
   "description": "JavaScript gcode slicer, Intended to use with the Doodle3D WiFi-Box # Usage",
   "main": "lib/index.js",
   "module": "module/index.js",
@@ -14,7 +14,7 @@
     "build:module:settings": "cp -r src/settings module"
   },
   "dependencies": {
-    "@doodle3d/clipper-js": "^1.0.3",
+    "@doodle3d/clipper-js": "^1.0.7",
     "three": "^0.83.0"
   },
   "devDependencies": {
diff --git a/src/sliceActions/shapesToSlices.js b/src/sliceActions/shapesToSlices.js
index 2d0fe94..9553c67 100644
--- a/src/sliceActions/shapesToSlices.js
+++ b/src/sliceActions/shapesToSlices.js
@@ -20,11 +20,8 @@ export default function shapesToSlices(shapes, settings) {
     lineShapesClosed = new Shape(lineShapesClosed, true, true, true, true)
       .clean(cleanDelta);
 
-    lineShapesOpen = new Shape(lineShapesOpen, false, true, true, true);
-    //   .clean(cleanDelta);
-    // TODO
-    // Cleaning is actually wanted here but there is a bug in the clean function
-    // https://sourceforge.net/p/jsclipper/tickets/16/
+    lineShapesOpen = new Shape(lineShapesOpen, false, true, true, true)
+      .clean(cleanDelta);
 
     const slice = new Slice();
 
diff --git a/src/sliceActions/slicesToGCode.js b/src/sliceActions/slicesToGCode.js
index 96e1db3..a3dda02 100644
--- a/src/sliceActions/slicesToGCode.js
+++ b/src/sliceActions/slicesToGCode.js
@@ -50,9 +50,10 @@ export default function slicesToGCode(slices, settings) {
 
     for (let i = 0; i < slice.parts.length; i ++) {
       const part = slice.parts[i];
-      const outline = part.shell[0];
 
       if (part.closed) {
+        const outline = part.shell[0];
+
         for (let i = 0; i < part.shell.length; i ++) {
           const shell = part.shell[i];
           const isOuterShell = i === 0;
diff --git a/src/slicer.worker.js b/src/slicer.worker.js
index 7c0bc37..59bb2ce 100644
--- a/src/slicer.worker.js
+++ b/src/slicer.worker.js
@@ -1,3 +1,4 @@
+import 'core-js'; // polyfills
 import slice from './sliceActions/slice.js';
 import * as THREE from 'three';