diff --git a/src/plugins/navigation/public/top_nav_menu/top_nav_menu_item.tsx b/src/plugins/navigation/public/top_nav_menu/top_nav_menu_item.tsx
index 0c00a74d3344c..84232d47fd337 100644
--- a/src/plugins/navigation/public/top_nav_menu/top_nav_menu_item.tsx
+++ b/src/plugins/navigation/public/top_nav_menu/top_nav_menu_item.tsx
@@ -81,7 +81,7 @@ export function TopNavMenuItem(props: TopNavMenuData & { isMobileMenu?: boolean
     ) : props.emphasize ? (
       // fill is not compatible with EuiHeaderLink
       <EuiButton
-        size={!props.isMobileMenu ? 's' : undefined}
+        size="s"
         fullWidth={props.isMobileMenu}
         {...commonButtonProps}
         fill={props.fill ?? true}