diff --git a/src/editor-component.coffee b/src/editor-component.coffee
index 095c6451d..5d083b145 100644
--- a/src/editor-component.coffee
+++ b/src/editor-component.coffee
@@ -238,6 +238,7 @@ EditorCompont = React.createClass
 
   observeConfig: ->
     @subscribe atom.config.observe 'editor.fontFamily', @setFontFamily
+    @subscribe atom.config.observe 'editor.fontSize', @setFontSize
 
   setFontSize: (fontSize) ->
     @clearScopedCharWidths()