diff --git a/lib/ace/split.js b/lib/ace/split.js
index a6745002..1c9cdebe 100644
--- a/lib/ace/split.js
+++ b/lib/ace/split.js
@@ -153,6 +153,7 @@ var Split = function(container, theme, splits) {
         this.$editors.forEach(callback, scope);
     };
 
+    this.$fontSize = "";
     this.setFontSize = function(size) {
         this.$fontSize = size;
         this.forEach(function(editor) {