diff --git a/packages/core/src/components/radio-group/radio-group-item.tsx b/packages/core/src/components/radio-group/radio-group-item.tsx
index 60071f9..3eb46e3 100644
--- a/packages/core/src/components/radio-group/radio-group-item.tsx
+++ b/packages/core/src/components/radio-group/radio-group-item.tsx
@@ -23,7 +23,7 @@ export function RadioGroupItem(props: RadioGroupItemProps): JSX.Element {
     <button
       type="button"
       role="radio"
-      aria-checked={isChecked()}
+      aria-checked={isChecked() ? "true" : "false"}
       data-state={isChecked() ? "checked" : "unchecked"}
       disabled={isDisabled()}
       tabIndex={isChecked() ? 0 : -1}