diff --git a/packages/@react-types/radio/src/index.d.ts b/packages/@react-types/radio/src/index.d.ts
index 5646a4ed95e..383832e8e73 100644
--- a/packages/@react-types/radio/src/index.d.ts
+++ b/packages/@react-types/radio/src/index.d.ts
@@ -30,7 +30,7 @@ import {
 } from '@react-types/shared';
 import {ReactElement, ReactNode} from 'react';
 
-export interface RadioGroupProps extends ValueBase<string|null, string>, InputBase, Pick<InputDOMProps, 'name'>, Validation<string | null>, LabelableProps, HelpTextProps, FocusEvents {
+export interface RadioGroupProps extends ValueBase<string|null, string>, InputBase, Pick<InputDOMProps, 'name'>, Validation<string>, LabelableProps, HelpTextProps, FocusEvents {
   /**
    * The axis the Radio Button(s) should align with.
    * @default 'vertical'