diff --git a/book/_static/books.html b/book/_static/books.html
index a9648e5..5f8515a 100644
--- a/book/_static/books.html
+++ b/book/_static/books.html
@@ -115,6 +115,9 @@
         button.innerHTML = "Evaluate";
         button.onclick = eval;
         outputContainer.appendChild(button);
+
+        // Call func with initial values
+        eval();
     </script>
 </body>
 </html>
\ No newline at end of file