diff --git a/package.json b/package.json
index 8c11ac6..0b6d86f 100755
--- a/package.json
+++ b/package.json
@@ -4,6 +4,7 @@
   "description": "Lexes ES modules returning their import/export metadata",
   "main": "dist/lexer.cjs",
   "module": "dist/lexer.js",
+  "sideEffects": false,
   "types": "types/lexer.d.ts",
   "exports": {
     ".": {