diff --git a/viewer/src/App.js b/viewer/src/App.js
index 16617f2..c0c31e6 100644
--- a/viewer/src/App.js
+++ b/viewer/src/App.js
@@ -85,7 +85,7 @@ function App() {
       
       <a href={ rocketeer.image } className="button">Download Jpeg</a>
 
-      <a href='/#' onClick={ rocketeer.image.replace( 'jpg', 'svg' ) } className="button">Download Svg</a>
+      <a href='/#' onClick={ rocketeer?.image?.replace( 'jpg', 'svg' ) } className="button">Download Svg</a>
 
     </div>