diff --git a/lib/ace/document.js b/lib/ace/document.js
index 492c8050..985e2091 100644
--- a/lib/ace/document.js
+++ b/lib/ace/document.js
@@ -56,7 +56,7 @@ var Document = function(text) {
     oop.implement(this, EventEmitter);
 
     this.setValue = function(text) {
-        this.remove(new Range(0, 0, this.$lines.length, this.$lines[this.$lines.length-1].length));
+        this.remove(new Range(0, 0, this.$lines.length, this.getLine(this.$lines.length-1).length));
         this.insertLines(0, this.$split(text));
     };