diff --git a/src/PropTypes.js b/src/PropTypes.js
index cf120e4..364cd98 100644
--- a/src/PropTypes.js
+++ b/src/PropTypes.js
@@ -8,7 +8,7 @@ export function configStyleValidator(config) {
 }
 
 export default {
-  style(props, propName, componentName, ...rest) {
+  style: function style(props, propName, componentName, ...rest) {
     if (props[propName] == null) {
       return undefined
     }