diff --git a/browser/main/Detail/ToggleDirectionButton.js b/browser/main/Detail/ToggleDirectionButton.js
index 4fe41e0c..b69cb1b7 100644
--- a/browser/main/Detail/ToggleDirectionButton.js
+++ b/browser/main/Detail/ToggleDirectionButton.js
@@ -20,7 +20,7 @@ const ToggleDirectionButton = ({ onClick, isRTL }) => (
 
 ToggleDirectionButton.propTypes = {
   onClick: PropTypes.func.isRequired,
-  isRTL: PropTypes.string.isRequired
+  isRTL: PropTypes.bool.isRequired
 }
 
 export default CSSModules(ToggleDirectionButton, styles)