diff --git a/lib/ace/elastic_tabstops.js b/lib/ace/elastic_tabstops.js
index 85162cc5..c3fa0411 100644
--- a/lib/ace/elastic_tabstops.js
+++ b/lib/ace/elastic_tabstops.js
@@ -214,7 +214,7 @@ var ElasticTabstops = function(editor, session) {
             if (difference > 0) {
                 // put the spaces after the tab and then delete the tab, so any insertion
                 // points behave as expected
-                this.$session.getDocument().insertInLine({row: row, column: it + 1}, Array(difference).join(" ") + "\t");
+                this.$session.getDocument().insertInLine({row: row, column: it + 1}, Array(difference + 1).join(" ") + "\t");
                 this.$session.getDocument().removeInLine(row, it, it + 1);
 
                 bias += difference;