diff --git a/js/wasm/svelte/DownloadLink.svelte b/js/wasm/svelte/DownloadLink.svelte
index f0b016211ed0e..609f66f1ab487 100644
--- a/js/wasm/svelte/DownloadLink.svelte
+++ b/js/wasm/svelte/DownloadLink.svelte
@@ -33,7 +33,7 @@
 			throw new Error("Wasm worker proxy is not available.");
 		}
 
-		const url = new URL(href);
+		const url = new URL(href, window.location.href);
 		const path = url.pathname;
 
 		is_downloading = true;
diff --git a/js/wasm/svelte/file-url.ts b/js/wasm/svelte/file-url.ts
index 5e874dd4ebbaa..493e96e280ac6 100644
--- a/js/wasm/svelte/file-url.ts
+++ b/js/wasm/svelte/file-url.ts
@@ -9,7 +9,7 @@ export function should_proxy_wasm_src(src: MediaSrc): boolean {
 		return false;
 	}
 
-	const url = new URL(src);
+	const url = new URL(src, window.location.href);
 	if (!is_self_host(url)) {
 		// `src` is not accessing a local server resource, so we don't need to proxy this request to the Wasm worker.
 		return false;
@@ -33,7 +33,7 @@ export async function resolve_wasm_src(src: MediaSrc): Promise<MediaSrc> {
 		return src;
 	}
 
-	const url = new URL(src);
+	const url = new URL(src, window.location.href);
 	const path = url.pathname;
 	return maybeWorkerProxy
 		.httpRequest({