diff --git a/demo/default.htm b/demo/default.htm
index 44d8c33d..72a8267a 100644
--- a/demo/default.htm
+++ b/demo/default.htm
@@ -11,7 +11,7 @@
 <body>
   <div class="flex-rows">
     <div class="flex-columns inset">
-      <header>markdownlint demo</header>
+      <header>markdownlint demo <span id="version" class="detail"></span></header>
       <div class="flex-fill"></div>
       <form>
         <input id="openFile" type="file"/>
diff --git a/demo/default.js b/demo/default.js
index 1e2753dc..0d74422a 100644
--- a/demo/default.js
+++ b/demo/default.js
@@ -164,6 +164,10 @@
     e.preventDefault();
   }
 
+  // Show library version
+  document.getElementById("version").textContent =
+    "(v" + markdownlint.getVersion() + ")";
+
   // Add event listeners
   document.body.addEventListener("dragover", onDragOver);
   document.body.addEventListener("drop", onDrop);
