diff --git a/examples/jspsych-categorize-html.html b/examples/jspsych-categorize-html.html
index d4cd2463..1c3f066e 100644
--- a/examples/jspsych-categorize-html.html
+++ b/examples/jspsych-categorize-html.html
@@ -15,7 +15,7 @@
 <script>
   var trial = {
     type: 'categorize-html',
-    stimulus: '<div style="margin: auto; width: 200px; height: 200px; background-color: blue;></div>"',
+    stimulus: '<div style="margin: auto; width: 200px; height: 200px; background-color: blue;"></div>',
     key_answer: 66,
     choices: [66, 80],
     text_answer: 'happy',