diff --git a/mellon/views.py b/mellon/views.py
index babf813..889d40b 100644
--- a/mellon/views.py
+++ b/mellon/views.py
@@ -348,12 +348,14 @@ class LoginView(ProfileMixin, LogMixin, View):
         return self.sso_failure(request, login, reason=idp_message, status_codes=status_codes)
 
     def request_discovery_service(self, request, is_passive=False):
-        self_url = request.build_absolute_uri() + '&nodisco=1'
+        return_url = request.build_absolute_uri()
+        return_url += '&' if '?' in return_url else '?'
+        return_url += 'nodisco=1'
         url = app_settings.DISCOVERY_SERVICE_URL
         params = {
             # prevent redirect loops with the discovery service
             'entityID': request.build_absolute_uri(reverse('mellon_metadata')),
-            'return': self_url,
+            'return': return_url,
         }
         if is_passive:
             params['isPassive'] = 'true'
diff --git a/tests/test_views.py b/tests/test_views.py
index 9292de7..014af86 100644
--- a/tests/test_views.py
+++ b/tests/test_views.py
@@ -147,7 +147,7 @@ def test_sp_initiated_login_discovery_service_passive(private_settings, client):
     assert response['Location'].startswith('https://disco?')
     assert params == {'isPassive': ['true'],
                       'entityID': ['http://testserver/metadata/'],
-                      'return': ['http://testserver/login/?nodisco=1']}
+                      'return': ['http://testserver/login/?passive=1&nodisco=1']}
 
 
 def test_sp_initiated_login_discovery_service_nodisco(private_settings, client):