diff --git a/packages/hwp.js/package.json b/packages/hwp.js/package.json
index 73d9da0..cefc805 100644
--- a/packages/hwp.js/package.json
+++ b/packages/hwp.js/package.json
@@ -11,7 +11,7 @@
     "module": "./build/esm.js",
     "types": "./build/index.d.ts"
   },
-  "siseEffect": false,
+  "sideEffect": false,
   "repository": {
     "type": "git",
     "url": "https://github.com/hahnlee/hwp.js.git"
diff --git a/packages/viewer/package.json b/packages/viewer/package.json
index e1f8060..6b48de6 100644
--- a/packages/viewer/package.json
+++ b/packages/viewer/package.json
@@ -5,7 +5,7 @@
   "main": "./src/index.ts",
   "module": "./src/index.ts",
   "types": "./src/index.ts",
-  "siseEffect": false,
+  "sideEffect": false,
   "publishConfig": {
     "main": "./build/cjs.js",
     "module": "./build/esm.js",