diff --git a/demo/demo.py b/demo/demo.py
index bed7413..2b38192 100644
--- a/demo/demo.py
+++ b/demo/demo.py
@@ -102,7 +102,7 @@ def make_app():
     settings['mako.directories'] = __name__ + ':templates'
     settings['mako.module_directory'] = __name__ + ':mako_modules'
     settings['debugtoolbar.reload_templates'] = True
-    settings['debugtoolbar.hosts'] = ['127.0.0.1']
+    settings['debugtoolbar.hosts'] = ['::1', '127.0.0.1']
     settings['debugtoolbar.intercept_redirects'] = True
     settings['debugtoolbar.exclude_prefixes'] = ['/static', '/favicon.ico']
 
@@ -139,6 +139,5 @@ def make_app():
 app = make_app()
 
 if __name__ == '__main__':
-    from wsgiref.simple_server import make_server
-    httpd = make_server('', 8080, app)
-    httpd.serve_forever()
+    from waitress import serve
+    serve(app, listen='localhost:8080')
diff --git a/demo/setup.py b/demo/setup.py
index 864e8c4..c6bba07 100644
--- a/demo/setup.py
+++ b/demo/setup.py
@@ -31,6 +31,7 @@
     'pyramid_chameleon',
     'selenium',
     'SQLAlchemy',
+    'waitress',
     ]
 
 setup(name='debugtoolbar_demo',
diff --git a/src/pyramid_debugtoolbar/toolbar.py b/src/pyramid_debugtoolbar/toolbar.py
index 156168d..58b9d0e 100644
--- a/src/pyramid_debugtoolbar/toolbar.py
+++ b/src/pyramid_debugtoolbar/toolbar.py
@@ -266,7 +266,6 @@ def toolbar_tween(request):
             request, panel_classes, global_panel_classes, default_active_panels
         )
         request.debug_toolbar = toolbar
-        request_history.put(request.pdtb_id, toolbar)
 
         _handler = handler
         for panel in toolbar.panels:
@@ -350,6 +349,11 @@ def toolbar_tween(request):
             return response
 
         finally:
+            # do not add the request until it is complete, some panels
+            # do not properly support rendering while the request is still
+            # processing
+            request_history.put(request.pdtb_id, toolbar)
+
             # break circref
             del request.debug_toolbar