diff --git a/lib/ace/editor.js b/lib/ace/editor.js
index b4681bcc..02f87fcd 100644
--- a/lib/ace/editor.js
+++ b/lib/ace/editor.js
@@ -1273,14 +1273,14 @@ var Editor = function(renderer, session) {
         this.$blockScrolling++;
         this.session.getUndoManager().undo();
         this.$blockScrolling--;
-        renderer.scrollCursorIntoView(null, 0.5);
+        this.renderer.scrollCursorIntoView(null, 0.5);
     };
 
     this.redo = function() {
         this.$blockScrolling++;
         this.session.getUndoManager().redo();
         this.$blockScrolling--;
-        renderer.scrollCursorIntoView(null, 0.5);
+        this.renderer.scrollCursorIntoView(null, 0.5);
     };
 
     this.destroy = function() {