diff --git a/authentic2_idp_ltpa/views.py b/authentic2_idp_ltpa/views.py
index d0d9446..b8756c6 100644
--- a/authentic2_idp_ltpa/views.py
+++ b/authentic2_idp_ltpa/views.py
@@ -16,7 +16,7 @@ def ltpa(request):
     secret = utils.decode_secret(app_settings.TOKEN_SECRET)
     user = adapter.get_adapter().get_username(request)
     token = utils.generate_domino_ltpa_token(user, secret)
-    domain = app_settings.COOKIE_DOMAIN or request.META['HTTP_HOST']
+    domain = app_settings.COOKIE_DOMAIN or request.META['HTTP_HOST'].split(':')[0]
     response.set_cookie(app_settings.COOKIE_NAME, token, domain=domain,
             httponly=app_settings.COOKIE_HTTP_ONLY)
     return response