diff --git a/package.json b/package.json
index 82bfb79798..d65fa8bb78 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,8 @@
     "gulp-vulcanize": "^6.0.1",
     "lazypipe": "^0.2.3",
     "polyclean": "^1.2.0",
-    "run-sequence": "^1.1.0"
+    "run-sequence": "^1.1.0",
+    "web-component-tester": "^3.3.21"
   },
   "scripts": {
     "build": "node_modules/gulp/bin/gulp.js",