diff --git a/.changeset/violet-flowers-sell.md b/.changeset/violet-flowers-sell.md
new file mode 100644
index 0000000..adecd72
--- /dev/null
+++ b/.changeset/violet-flowers-sell.md
@@ -0,0 +1,5 @@
+---
+'@react-oauth/google': patch
+---
+
+Make `credential` property guaranteed in `onSuccess` callback
diff --git a/packages/@react-oauth/google/src/GoogleLogin.tsx b/packages/@react-oauth/google/src/GoogleLogin.tsx
index dc8777b..6f7eb68 100644
--- a/packages/@react-oauth/google/src/GoogleLogin.tsx
+++ b/packages/@react-oauth/google/src/GoogleLogin.tsx
@@ -12,8 +12,12 @@ import {
 
 const containerHeightMap = { large: 40, medium: 32, small: 20 };
 
+type SuccessfulCredentialResponse = Omit<CredentialResponse, 'credential'> & {
+  credential: string;
+};
+
 export type GoogleLoginProps = {
-  onSuccess: (credentialResponse: CredentialResponse) => void;
+  onSuccess: (credentialResponse: SuccessfulCredentialResponse) => void;
   onError?: () => void;
   promptMomentNotification?: MomentListener;
   useOneTap?: boolean;