diff --git a/packages/compiler/package.json b/packages/compiler/package.json
index edd6837a..4f04b367 100644
--- a/packages/compiler/package.json
+++ b/packages/compiler/package.json
@@ -5,6 +5,7 @@
   "main": "index.js",
   "module": "dist/compiler.esm-bundler.js",
   "typings": "dist/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"
@@ -18,4 +19,4 @@
     "url": "https://github.com/vuejs/vue/issues"
   },
   "homepage": "https://github.com/vuejs/vue/tree/dev/packages/compiler#readme"
-}
\ No newline at end of file
+}
diff --git a/packages/core/package.json b/packages/core/package.json
index f2c18036..29e9e086 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -5,6 +5,7 @@
   "main": "index.js",
   "module": "dist/core.esm-bundler.js",
   "typings": "dist/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"
diff --git a/packages/observer/package.json b/packages/observer/package.json
index 8150a7cd..d12346c8 100644
--- a/packages/observer/package.json
+++ b/packages/observer/package.json
@@ -6,6 +6,7 @@
   "module": "dist/observer.esm-bundler.js",
   "typings": "dist/index.d.ts",
   "unpkg": "dist/observer.global.js",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"
diff --git a/packages/renderer-dom/package.json b/packages/renderer-dom/package.json
index a45d035b..d4402b5c 100644
--- a/packages/renderer-dom/package.json
+++ b/packages/renderer-dom/package.json
@@ -6,6 +6,7 @@
   "module": "dist/renderer-dom.esm-bundler.js",
   "typings": "dist/index.d.ts",
   "unpkg": "dist/renderer-dom.global.js",
+  "sideEffects": false,
   "buildOptions": {
     "name": "VueDOMRenderer",
     "formats": ["esm", "cjs", "global", "esm-browser"]
diff --git a/packages/scheduler/package.json b/packages/scheduler/package.json
index 6898c2ff..60b35db1 100644
--- a/packages/scheduler/package.json
+++ b/packages/scheduler/package.json
@@ -5,6 +5,7 @@
   "main": "index.js",
   "module": "dist/scheduler.esm-bundler.js",
   "typings": "dist/index.d.ts",
+  "sideEffects": false,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/vuejs/vue.git"
diff --git a/packages/vue/package.json b/packages/vue/package.json
index 10cce245..45b9e306 100644
--- a/packages/vue/package.json
+++ b/packages/vue/package.json
@@ -6,6 +6,7 @@
   "module": "dist/vue.esm-bundler.js",
   "typings": "dist/index.d.ts",
   "unpkg": "dist/vue.global.js",
+  "sideEffects": false,
   "buildOptions": {
     "name": "Vue",
     "compat": true,