diff --git a/.changeset/hip-terms-watch.md b/.changeset/hip-terms-watch.md
new file mode 100644
index 000000000..585103b3f
--- /dev/null
+++ b/.changeset/hip-terms-watch.md
@@ -0,0 +1,5 @@
+---
+'@lion/checkbox-group': patch
+---
+
+Add define.js sideEffect to package.json
diff --git a/docs/components/inputs/checkbox-group/features.md b/docs/components/inputs/checkbox-group/features.md
index 6274421a2..fb0347191 100644
--- a/docs/components/inputs/checkbox-group/features.md
+++ b/docs/components/inputs/checkbox-group/features.md
@@ -3,8 +3,6 @@
 ```js script
 import { html } from '@lion/core';
 import '@lion/checkbox-group/define';
-import '@lion/checkbox-group/define';
-import '@lion/checkbox-group/define';
 ```
 
 ## Model value
diff --git a/packages/checkbox-group/package.json b/packages/checkbox-group/package.json
index f1342bb93..97b09ef20 100644
--- a/packages/checkbox-group/package.json
+++ b/packages/checkbox-group/package.json
@@ -33,6 +33,7 @@
     "test": "cd ../../ && npm run test:browser -- --group checkbox-group"
   },
   "sideEffects": [
+    "define.js",
     "lion-checkbox.js",
     "lion-checkbox-group.js",
     "lion-checkbox-indeterminate.js"