diff --git a/packages/fiori/src/SideNavigation.ts b/packages/fiori/src/SideNavigation.ts
index 33c66887444f..3e4d41c7cf1c 100644
--- a/packages/fiori/src/SideNavigation.ts
+++ b/packages/fiori/src/SideNavigation.ts
@@ -492,17 +492,19 @@ class SideNavigation extends UI5Element {
 
 			let itemDomRef;
 
-			if (isInstanceOfSideNavigationItemBase(item)) {
-				itemDomRef = item.getDomRef()!;
+			if (isInstanceOfSideNavigationItemBase(item) && item.getDomRef()) {
+				itemDomRef = item.getDomRef();
 			} else {
 				itemDomRef = item;
 			}
 
-			const { marginTop, marginBottom } = window.getComputedStyle(itemDomRef);
-			itemsHeight += itemDomRef.offsetHeight + parseFloat(marginTop) + parseFloat(marginBottom);
+			if (itemDomRef) {
+				const { marginTop, marginBottom } = window.getComputedStyle(itemDomRef);
+				itemsHeight += itemDomRef.offsetHeight + parseFloat(marginTop) + parseFloat(marginBottom);
 
-			if (itemsHeight > listHeight) {
-				item.classList.add("ui5-sn-item-hidden");
+				if (itemsHeight > listHeight) {
+					item.classList.add("ui5-sn-item-hidden");
+				}
 			}
 		});