diff --git a/.docker/images/nginx/location_prepend_simplesamlphp.conf b/.docker/images/nginx/location_prepend_simplesamlphp.conf
index 190e5e9a4..ec5896e12 100644
--- a/.docker/images/nginx/location_prepend_simplesamlphp.conf
+++ b/.docker/images/nginx/location_prepend_simplesamlphp.conf
@@ -19,3 +19,10 @@ location ~ /${LAGOON_PROJECT:-govcms}-saml/module.php/saml/sp/(saml2-logout\.php
         }
 }
 
+# Serve only static assets (JS/CSS/images) for SAML auto-post page.
+location ^~ /${LAGOON_PROJECT:-govcms}-saml/assets/ {
+    alias /app/vendor/simplesamlphp/simplesamlphp/public/assets/;
+    access_log off;
+    expires 1h;
+    add_header Cache-Control "public";
+}