diff --git a/src/web.js b/src/web.js
index 6a383df..b1cecd5 100644
--- a/src/web.js
+++ b/src/web.js
@@ -225,6 +225,24 @@ async function start() {
   });
 
 
+  app.use(function (req, res, next) {
+    const pathName = String(req.originalUrl || '');
+    const wantsHtml = !pathName.startsWith('/api/') && (!req.accepts || req.accepts('html'));
+
+    if (!wantsHtml) {
+      return next();
+    }
+
+    return res.status(404).send(pages.renderErrorPage({
+      statusCode: 404,
+      title: 'Not found',
+      errorTitle: 'Oops! Page not found.',
+      message: 'We could not find the page you were looking for.',
+      backUrl: req.currentUser ? '/admin' : '/login',
+      backLabel: req.currentUser ? 'Back to dashboard' : 'Sign in'
+    }, req.currentUser));
+  });
+
   app.use(function (error, req, res, _next) {
     console.error(error);
     const statusCode = Number(error && (error.statusCode || error.status)) || 500;