diff --git a/lib/ace/document.js b/lib/ace/document.js
index 985e2091..bb25eeb6 100644
--- a/lib/ace/document.js
+++ b/lib/ace/document.js
@@ -56,7 +56,8 @@ var Document = function(text) {
     oop.implement(this, EventEmitter);
 
     this.setValue = function(text) {
-        this.remove(new Range(0, 0, this.$lines.length, this.getLine(this.$lines.length-1).length));
+        var len = this.getLength();
+        this.remove(new Range(0, 0, len, this.getLine(len-1).length));
         this.insertLines(0, this.$split(text));
     };
   	
@@ -151,7 +152,7 @@ var Document = function(text) {
     };
 
     this.$clipPosition = function(position) {
-        var length = this.$lines.length;
+        var length = this.getLength();
         if (position.row >= length) {
             position.row = Math.max(0, length - 1);
             position.column = this.getLine(length-1).length;