diff --git a/frontend/src/api/admin.ts b/frontend/src/api/admin.ts
index d3589a6..f10415c 100644
--- a/frontend/src/api/admin.ts
+++ b/frontend/src/api/admin.ts
@@ -34,9 +34,9 @@ export const adminRateLimitsApi = {
   list: (): Promise<AdminRateLimit[]> =>
     api.get<AdminRateLimit[]>('/admin/rate-limits'),
 
-  /** PUT /admin/rate-limits/:id -- update max requests / time window for a provider. */
-  update: (id: string, data: UpdateRateLimitRequest): Promise<AdminRateLimit> =>
-    api.put<AdminRateLimit>(`/admin/rate-limits/${id}`, data),
+  /** PUT /admin/rate-limits/:provider_name -- update rate limit for a specific provider. */
+  update: (providerName: string, data: UpdateRateLimitRequest): Promise<AdminRateLimit> =>
+    api.put<AdminRateLimit>(`/admin/rate-limits/${providerName}`, data),
 };
 
 /** Admin user management endpoints. */
diff --git a/frontend/src/pages/admin/RateLimits.tsx b/frontend/src/pages/admin/RateLimits.tsx
index b4fabc0..e6f6d96 100644
--- a/frontend/src/pages/admin/RateLimits.tsx
+++ b/frontend/src/pages/admin/RateLimits.tsx
@@ -67,7 +67,7 @@ const RateLimits: Component = () => {
   const handleSave = async (limit: LocalRateLimit) => {
     setSavingId(limit.id);
     try {
-      await adminRateLimitsApi.update(limit.id, {
+      await adminRateLimitsApi.update(limit.provider_name, {
         max_requests: limit.max_requests,
         time_window_seconds: limit.time_window_seconds,
       });