diff --git a/lib/ace/editor.js b/lib/ace/editor.js
index 4055d2b2..807d1d2a 100644
--- a/lib/ace/editor.js
+++ b/lib/ace/editor.js
@@ -228,9 +228,15 @@ var Editor =function(renderer, session) {
     };
 
     this.onDocumentChange = function(e) {
-        var data = e.data;
-        this.bgTokenizer.start(data.firstRow);
-        this.renderer.updateLines(data.firstRow, data.lastRow);
+        var delta = e.data;
+        var range = delta.range;
+        
+        this.bgTokenizer.start(range.start.row);
+        if (range.start.row == range.end.row)
+            var lastRow = range.end.row;
+        else 
+            lastRow = Infinity;
+        this.renderer.updateLines(range.start.row, lastRow);
 
         // update cursor because tab characters can influence the cursor position
         this.renderer.updateCursor(this.getCursorPosition(), this.$overwrite);