diff --git a/src/resources/radar/bgp/routes.ts b/src/resources/radar/bgp/routes.ts
index af5f8e3343..da442eab67 100644
--- a/src/resources/radar/bgp/routes.ts
+++ b/src/resources/radar/bgp/routes.ts
@@ -26,7 +26,7 @@ export class Routes extends APIResource {
   }
 
   /**
-   * Lookup prefix-to-origin mapping on global routing tables.
+   * Lookup prefix-to-ASN mapping on global routing tables.
    */
   pfx2as(query?: RoutePfx2asParams, options?: Core.RequestOptions): Core.APIPromise<RoutePfx2asResponse>;
   pfx2as(options?: Core.RequestOptions): Core.APIPromise<RoutePfx2asResponse>;
@@ -267,13 +267,19 @@ export interface RoutePfx2asParams {
    */
   format?: 'JSON' | 'CSV';
 
+  /**
+   * Return only results with the longest prefix match for the given prefix. For
+   * example, specify a /32 prefix to lookup the origin ASN for an IPv4 address.
+   */
+  longestPrefixMatch?: boolean;
+
   /**
    * Lookup prefixes originated by the given ASN
    */
   origin?: number;
 
   /**
-   * Lookup origins of the given prefix
+   * Lookup origin ASNs of the given prefix
    */
   prefix?: string;
 
diff --git a/tests/api-resources/radar/bgp/routes.test.ts b/tests/api-resources/radar/bgp/routes.test.ts
index c1bf37cc0f..6af728828a 100644
--- a/tests/api-resources/radar/bgp/routes.test.ts
+++ b/tests/api-resources/radar/bgp/routes.test.ts
@@ -66,7 +66,7 @@ describe('resource routes', () => {
     // ensure the request options are being passed correctly by passing an invalid HTTP method in order to cause an error
     await expect(
       cloudflare.radar.bgp.routes.pfx2as(
-        { format: 'JSON', origin: 0, prefix: '1.1.1.0/24', rpkiStatus: 'INVALID' },
+        { format: 'JSON', longestPrefixMatch: true, origin: 0, prefix: '1.1.1.0/24', rpkiStatus: 'INVALID' },
         { path: '/_stainless_unknown_path' },
       ),
     ).rejects.toThrow(Cloudflare.NotFoundError);