diff --git a/website/static/playground.js b/website/static/playground.js
index 078edbb48..589366cd2 100644
--- a/website/static/playground.js
+++ b/website/static/playground.js
@@ -291,6 +291,10 @@ function setEditorStyles() {
   outputEditor.setOption("mode", mode);
   output2Editor.setOption("mode", mode);
 
+  inputEditor.setOption("rulers", [
+    { column: options.printWidth, color: "#eeeeee" }
+  ]);
+
   [outputEditor, output2Editor].forEach(function(editor) {
     editor.setOption("rulers", [
       { column: options.printWidth, color: "#444444" }