diff --git a/web-frontend/src/routes/+page.svelte b/web-frontend/src/routes/+page.svelte
index 01fe759..edab529 100644
--- a/web-frontend/src/routes/+page.svelte
+++ b/web-frontend/src/routes/+page.svelte
@@ -226,7 +226,7 @@
 
 	{#if $url && $url.hash}
 		<a class="text-indigo-600" href={$url}>Permalink</a>
-		<CopyButton data={$url} />
+		<CopyButton data={'' + $url} />
 	{/if}
 
 	<CoordinateInput