diff --git a/share/manifest b/share/manifest
index fb38d05..21d12f3 100644
--- a/share/manifest
+++ b/share/manifest
@@ -35,7 +35,7 @@ $css
 # entry point of pdf2htmlEX
 """
 <script type="text/javascript">
-new pdf2htmlEX.Viewer({
+window.pdf2htmlEXViewerInstance = new pdf2htmlEX.Viewer({
     container_id : 'page-container', 
     sidebar_id : 'sidebar',
     outline_id : 'outline',