Fix viewAjaxCallback might be called on null

1 files changed, 1 insertions, 1 deletions

diff --git a/public/js/syncscroll.js b/public/js/syncscroll.js
index b2fee76c..47d0e1c4 100644
--- a/public/js/syncscroll.js
+++ b/public/js/syncscroll.js
@@ -138,7 +138,7 @@ function setupSyncAreas(edit, view, markdown) {
 
 var scrollMap, lineHeightMap, viewTop, viewBottom;
 
-viewAjaxCallback = clearMap;
+window.viewAjaxCallback = clearMap;
 
 function clearMap() {
     scrollMap = null;