diff --git a/src/components/input/radio/index.js b/src/components/input/radio/index.js
index a0e094881..5e4ae81e9 100644
--- a/src/components/input/radio/index.js
+++ b/src/components/input/radio/index.js
@@ -77,7 +77,7 @@ class Radio extends Component {
         const validInputProps = filterProps(this.props);
 
         validInputProps.onChange = this._onChange;
-        validInputProps.checked = isChecked ? 'checked' : undefined;
+        validInputProps.checked = isChecked ? 'checked' : '';
         const inputProps = { ...validInputProps };
 
         return (