diff --git a/packages/rhf-mui/src/RadioButtonGroup.tsx b/packages/rhf-mui/src/RadioButtonGroup.tsx
index 5814a46..e116cb4 100644
--- a/packages/rhf-mui/src/RadioButtonGroup.tsx
+++ b/packages/rhf-mui/src/RadioButtonGroup.tsx
@@ -98,7 +98,8 @@ const RadioButtonGroup = forwardRef(function RadioButtonGroup<
     : helperText
 
   const onRadioChange = (event: ChangeEvent<HTMLInputElement>) => {
-    const radioValue = (event.target as HTMLInputElement).value
+    const radioValue =
+      type === 'number' ? Number(event.target.value) : event.target.value
     const returnValue = returnObject
       ? options.find((items) => items[valueKey] === radioValue)
       : radioValue