diff --git a/auth/oauth.py b/auth/oauth.py
index 413fab28..1837ed4b 100644
--- a/auth/oauth.py
+++ b/auth/oauth.py
@@ -769,6 +769,10 @@ async def oauth_callback_http(request: Request) -> JSONResponse | RedirectRespon
                     "code_verifier": code_verifier,
                 }
 
+                # Google требует client_secret даже при использовании PKCE
+                if hasattr(client, "client_secret") and client.client_secret:
+                    token_data["client_secret"] = client.client_secret
+
                 async with httpx.AsyncClient() as http_client:
                     response = await http_client.post(
                         token_endpoint, data=token_data, headers={"Accept": "application/json"}