diff --git a/app/app/settings/prod.py b/app/app/settings/prod.py
index d7ca1b6..7f34f14 100644
--- a/app/app/settings/prod.py
+++ b/app/app/settings/prod.py
@@ -28,7 +28,7 @@
     ]
 
 CSRF_TRUSTED_ORIGINS = [
-    HOSTNAME,
+    f"https://{HOSTNAME}",
 ]
 
 # Use manifest to manage static file versions for cache busting: