diff --git a/package.json b/package.json
index 793b9c7..06d64af 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
     "test": "npm run travis",
     "prebuild": "parcel build --global Filer src/index.js --no-minify --out-file filer.js",
     "build": "parcel build --global Filer src/index.js --out-file filer.min.js --detailed-report",
-    "prekarma-mocha": "parcel build tests/index.js --out-dir tests/dist",
+    "prekarma-mocha": "parcel build tests/index.js --no-source-maps --out-dir tests/dist",
     "karma-mocha": "karma start karma.conf.js"
   },
   "repository": {