diff --git a/packages/common/src/Client.ts b/packages/common/src/Client.ts
index 9c9fa61..e10b980 100644
--- a/packages/common/src/Client.ts
+++ b/packages/common/src/Client.ts
@@ -17,7 +17,7 @@ export const client = <const Record extends { readonly [_: string]: Api.ApiAny }
 	{ baseUrl }: ClientOptions = {},
 ) => {
 	return Object.freeze(Record.map(bundle.record, (api, key) => {
-		const url = new URL(`/api/${key}`, baseUrl);
+		const url = new URL(`/api/${key}`, baseUrl ?? location.origin);
 
 		const requestEncoder = encodeBody(api.request);
 		const responseDecoder = decodeBody(api.response);