diff --git a/src/demo.html b/src/demo.html
index 438d421a..b578a0e3 100644
--- a/src/demo.html
+++ b/src/demo.html
@@ -72,6 +72,7 @@ <h1>MicroPython-micro:bit simulator example embedding</h1>
             title="Simulator"
             frameborder="0"
             scrolling="no"
+            sandbox="allow-scripts allow-same-origin"
           ></iframe>
           <div id="sensors" class="column"></div>
         </div>