diff --git a/server/portal-published-page-delivery.mjs b/server/portal-published-page-delivery.mjs
index f6c1b9c..bff9b91 100644
--- a/server/portal-published-page-delivery.mjs
+++ b/server/portal-published-page-delivery.mjs
@@ -172,7 +172,7 @@ export function createPortalPublishedPageDelivery({
     }
     const origin = resolveRequestOrigin(req);
     const referrerHint = String(
-      req.headers.referer ?? req.headers.referrer ?? req.get?.('referer') ?? '',
+      req.headers?.referer ?? req.headers?.referrer ?? req.get?.('referer') ?? '',
     ).trim();
     const originalPath =
       req.originalUrl || req.url || '';
diff --git a/server/portal-workspace-publication-delivery.mjs b/server/portal-workspace-publication-delivery.mjs
index 5ff3579..c1703d1 100644
--- a/server/portal-workspace-publication-delivery.mjs
+++ b/server/portal-workspace-publication-delivery.mjs
@@ -263,7 +263,7 @@ export function createPortalWorkspacePublicationDelivery({
         analyticsConfig,
       ),
       referrerHint: String(
-        req.headers.referer ?? req.headers.referrer ?? req.get?.('referer') ?? '',
+        req.headers?.referer ?? req.headers?.referrer ?? req.get?.('referer') ?? '',
       ).trim(),
       config: analyticsConfig,
     });