diff --git a/package.json b/package.json
index e0e0c75..abb9005 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,7 @@
     "@11ty/eleventy-plugin-syntaxhighlight": "^2.0.3",
     "@open-wc/testing": "^2.4.2",
     "@open-wc/testing-karma": "^3.2.19",
+    "@rollup/plugin-replace": "^2.2.1",
     "@types/chai": "^4.2.7",
     "@types/mocha": "^5.2.7",
     "@typescript-eslint/eslint-plugin": "^2.12.0",