diff --git a/package.json b/package.json
index 40d79c6f3cdf592fd02e7f238b628c585d8b31aa..9f03014b5b1aa145f19d098cec32e6390f3eb009 100644
--- a/package.json
+++ b/package.json
@@ -16,8 +16,8 @@
     "package-es5": "cd dist/netex && cat runtime-es5.js polyfills-es5.js main-es5.js > bundle-es5.js",
     "package-es2015": "cd dist/netex && cat runtime-es2015.js polyfills-es2015.js main-es2015.js > bundle-es2015.js",
     "bundle": "npm run build-prod netex && npm run package-es5 && npm run package-es2015",
-    "build:netex": "python prefixCSS.py --stage parse && npm run build-prod netex && node build-netex.js && python prefixCSS.py --stage cleanup",
-    "build:netex-dev": "python prefixCSS.py --stage parse && npm run build-dev netex && node build-netex.js && python prefixCSS.py --stage cleanup",
+    "build:netex": "python3 prefixCSS.py --stage parse && npm run build-prod netex && node build-netex.js && python3 prefixCSS.py --stage cleanup",
+    "build:netex-dev": "python3 prefixCSS.py --stage parse && npm run build-dev netex && node build-netex.js && python3 prefixCSS.py --stage cleanup",
     "build:netex-old": "npm run build-old netex && node build-netex.js",
     "prefix": "bash prefix_styles.sh",
     "prefixcss": "postcss -r drugsTone-build/styles.css"