diff --git a/src/index.test.ts b/src/index.test.ts
index aa1f0bb..74ae0c7 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -41,4 +41,21 @@ describe('loadTossPayments', () => {
 
     expect(scripts).toHaveLength(1);
   });
+
+  test(`src를 지정하면 주어진 URL로 script를 로드한다`, async () => {
+    const testSource = `https://test.tosspayments.com/sdk`;
+    const { loadTossPayments } = await import('./index');
+
+    const loadPromise = loadTossPayments('test_key', {
+      src: `https://test.tosspayments.com/sdk`,
+    });
+
+    dispatchLoadEvent();
+
+    await loadPromise;
+
+    const script = document.querySelector(`script[src="${testSource}"]`);
+
+    expect(script).not.toBeNull();
+  });
 });
diff --git a/src/index.ts b/src/index.ts
index ef39652..fd1ee94 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -4,7 +4,10 @@ const SCRIPT_URL = 'https://js.tosspayments.com/v1';
 
 let cachedPromise: Promise<TossPaymentsInstance> | undefined;
 
-export function loadTossPayments(clientKey: string): Promise<TossPaymentsInstance> {
+export function loadTossPayments(
+  clientKey: string,
+  { src = SCRIPT_URL }: { src?: string } = {}
+): Promise<TossPaymentsInstance> {
   // SSR 지원
   if (typeof window === 'undefined') {
     return Promise.resolve({
@@ -17,7 +20,7 @@ export function loadTossPayments(clientKey: string): Promise<TossPaymentsInstanc
     });
   }
 
-  const selectedScript = document.querySelector(`script[src="${SCRIPT_URL}"]`);
+  const selectedScript = document.querySelector(`script[src="${src}"]`);
 
   if (selectedScript != null && cachedPromise !== undefined) {
     return cachedPromise;
@@ -28,7 +31,7 @@ export function loadTossPayments(clientKey: string): Promise<TossPaymentsInstanc
   }
 
   const script = document.createElement('script');
-  script.src = SCRIPT_URL;
+  script.src = src;
 
   cachedPromise = new Promise((resolve, reject) => {
     document.head.appendChild(script);