diff --git a/package.json b/package.json
index 723fe2f..1d427a1 100644
--- a/package.json
+++ b/package.json
@@ -17,9 +17,9 @@
     "url": "https://github.com/sReeper/d3-neighbour-sampling.git"
   },
   "scripts": {
-    "pretest": "rmdir /s /q build && mkdir build && rollup -g d3-force:d3,d3-dispatch:d3,d3-quadtree:d3,d3-collection:d3 -f umd -n d3 -o build/d3-neighbour-sampling.js -- index.js",
+    "pretest": "rm -rf build && mkdir build && rollup -g d3-force:d3,d3-dispatch:d3,d3-quadtree:d3,d3-collection:d3 -f umd -n d3 -o build/d3-neighbour-sampling.js -- index.js",
     "test": "tape 'test/**/*-test.js'",
-    "prepublish": "npm run test && uglifyjs build/d3-neighbour-sampling.js -c -m -o build/d3-neighbour-sampling.min.js",
+    "prepublish": "npm run test && node_modules/uglify-es/bin/uglifyjs build/d3-neighbour-sampling.js -c -m -o build/d3-neighbour-sampling.min.js",
     "postpublish": "zip -j build/d3-neighbour-sampling.zip -- LICENSE README.md build/d3-neighbour-sampling.js build/d3-neighbour-sampling.min.js"
   },
   "devDependencies": {
@@ -29,8 +29,9 @@
   },
   "dependencies": {
     "d3-collection": "^1.0.3",
-    "d3-force": "^1.0.6",
     "d3-dispatch": "^1.0.3",
-    "d3-quadtree": "^1.0.3"
+    "d3-force": "^1.0.6",
+    "d3-quadtree": "^1.0.3",
+    "uglify-es": "git+https://github.com/mishoo/UglifyJS2.git#harmony"
   }
 }