diff --git a/application/source/dom/updater.mjs b/application/source/dom/updater.mjs
index 7bd0381949eb84d3d8fc49190bf6245f71dfd698..6bb6459f2814cf9e889d3716057ca54f38ab2347 100644
--- a/application/source/dom/updater.mjs
+++ b/application/source/dom/updater.mjs
@@ -545,10 +545,13 @@ function internalTemplateLookUp(container, key, ref, path) {
 
     const rootNode = container.getRootNode();
     if (rootNode instanceof ShadowRoot) {
-        templateID = rootNode.host.getAttribute(ATTRIBUTE_UPDATER_INSERT_TEMPLATE_ID);
-        template = findDocumentTemplate(templateID, container);
-        if (template instanceof HTMLTemplateElement) {
-            return template;
+        const host = rootNode?.host;
+        if (host && host.hasAttribute(ATTRIBUTE_UPDATER_INSERT_TEMPLATE_ID)) {
+            templateID = host.getAttribute(ATTRIBUTE_UPDATER_INSERT_TEMPLATE_ID);
+            template = findDocumentTemplate(templateID, container);
+            if (template instanceof HTMLTemplateElement) {
+                return template;
+            }
         }
     }