diff --git a/packages/repl/package.json b/packages/repl/package.json
index 76f571163f..515db37a08 100644
--- a/packages/repl/package.json
+++ b/packages/repl/package.json
@@ -1,6 +1,7 @@
 {
 	"name": "@sveltejs/repl",
 	"version": "0.6.0",
+	"sideEffects": false,
 	"scripts": {
 		"dev": "vite dev",
 		"build": "vite build && npm run package",
diff --git a/packages/site-kit/package.json b/packages/site-kit/package.json
index 534a37e0ea..1a029592a2 100644
--- a/packages/site-kit/package.json
+++ b/packages/site-kit/package.json
@@ -1,6 +1,7 @@
 {
 	"name": "@sveltejs/site-kit",
 	"version": "6.0.0-next.64",
+	"sideEffects": false,
 	"description": "Styles and components for use in *.svelte.dev websites",
 	"type": "module",
 	"scripts": {