diff --git a/package-lock.json b/package-lock.json
index dc5a036..c71c4e0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "react-rest-request",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index bfcb17b..0bbfa0f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "react-rest-request",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "Minimalistic REST API client for React inspired by Apollo",
   "readme": "README.md",
   "main": "./target/index.js",
diff --git a/target/client.d.ts b/target/client.d.ts
index 45d62c6..53c1583 100644
--- a/target/client.d.ts
+++ b/target/client.d.ts
@@ -17,7 +17,7 @@ export declare type ClientResponse<Data extends Record<string, any>> = Readonly<
 export declare class Client {
     private config;
     constructor(config: ClientConfig);
-    private prepareRequest;
+    prepareRequest(props: PrepareRequestProps): Request;
     request<Data extends Record<string, any>>({ transformResponseData, ...restProps }: RequestProps<Data>): Promise<ClientResponse<Data>>;
 }
 export {};
diff --git a/target/client.js b/target/client.js
index b5c4fa5..73e7d6c 100644
--- a/target/client.js
+++ b/target/client.js
@@ -17,10 +17,16 @@ export class Client {
         this.config = config;
     }
     prepareRequest(props) {
+        var _a;
         const requestCanContainBody = [Method.POST, Method.PATCH, Method.PUT].includes(props.method);
-        const url = /https?:\/\//.test(props.url) ?
-            new URL(props.url)
-            : new URL(this.config.baseUrl + props.url);
+        const defaultBaseUrl = (_a = window) === null || _a === void 0 ? void 0 : _a.location.href;
+        const sourceUrl = /https?:\/\//.test(props.url) ?
+            props.url
+            : this.config.baseUrl + props.url;
+        if (!defaultBaseUrl && sourceUrl.startsWith('/')) {
+            throw new Error(`Invalid request method: ${sourceUrl}`);
+        }
+        const url = new URL(sourceUrl, defaultBaseUrl);
         if (!requestCanContainBody) {
             invariant(!(props.variables instanceof FormData), `Method ${props.method} cannot contain body`);
             url.search = urlSearchParamsFromObject(props.variables).toString();