diff --git a/combo/apps/pwa/views.py b/combo/apps/pwa/views.py
index 6eb6c792..d8b37856 100644
--- a/combo/apps/pwa/views.py
+++ b/combo/apps/pwa/views.py
@@ -47,7 +47,7 @@ def js_response(request, template_name, **kwargs):
     template = get_template(template_name)
     pwa_vapid_public_key = None
     pwa_settings = PwaSettings.singleton()
-    if pwa_settings.push_notifications:
+    if pwa_settings.push_notifications and hasattr(serialization.Encoding, 'X962'):
         if settings.PWA_VAPID_PUBLIK_KEY:  # legacy
             pwa_vapid_public_key = settings.PWA_VAPID_PUBLIK_KEY
         else: