diff --git a/packages/core/package.json b/packages/core/package.json
index 59751e5f..6d085d7d 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "build": "pnpm run -w build-package core",
         "gen-client": "node ./scripts/generate-client.cjs",
diff --git a/packages/dispatcher/package.json b/packages/dispatcher/package.json
index e69f0a4a..fa88cf73 100644
--- a/packages/dispatcher/package.json
+++ b/packages/dispatcher/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "distOnlyFields": {
         "exports": {
             ".": {
diff --git a/packages/file-id/package.json b/packages/file-id/package.json
index 751aae6a..4100bd6c 100644
--- a/packages/file-id/package.json
+++ b/packages/file-id/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "build": "pnpm run -w build-package file-id"
     },
diff --git a/packages/html-parser/package.json b/packages/html-parser/package.json
index 71a5ce54..ba92d720 100644
--- a/packages/html-parser/package.json
+++ b/packages/html-parser/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "build": "pnpm run -w build-package html-parser"
     },
diff --git a/packages/markdown-parser/package.json b/packages/markdown-parser/package.json
index 5ccea409..b6427eb0 100644
--- a/packages/markdown-parser/package.json
+++ b/packages/markdown-parser/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "build": "pnpm run -w build-package markdown-parser"
     },
diff --git a/packages/tl-runtime/package.json b/packages/tl-runtime/package.json
index 21ad32e3..341148b8 100644
--- a/packages/tl-runtime/package.json
+++ b/packages/tl-runtime/package.json
@@ -6,6 +6,7 @@
     "author": "Alina Sireneva <alina@tei.su>",
     "license": "MIT",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "docs": "typedoc",
         "build": "pnpm run -w build-package tl-runtime"
diff --git a/packages/tl-utils/package.json b/packages/tl-utils/package.json
index 60f304dc..d6216065 100644
--- a/packages/tl-utils/package.json
+++ b/packages/tl-utils/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "docs": "typedoc",
         "build": "pnpm run -w build-package tl-utils"
diff --git a/packages/wasm/package.json b/packages/wasm/package.json
index d95a75ee..c374ac42 100644
--- a/packages/wasm/package.json
+++ b/packages/wasm/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "docs": "typedoc",
         "build": "pnpm run -w build-package wasm",
diff --git a/packages/web/package.json b/packages/web/package.json
index 1bacc723..e7357550 100644
--- a/packages/web/package.json
+++ b/packages/web/package.json
@@ -7,6 +7,7 @@
     "license": "MIT",
     "main": "src/index.ts",
     "type": "module",
+    "sideEffects": false,
     "scripts": {
         "docs": "typedoc",
         "build": "pnpm run -w build-package web"