diff --git a/src/agents.ts b/src/agents.ts
index 9e29659..638b300 100644
--- a/src/agents.ts
+++ b/src/agents.ts
@@ -29,7 +29,7 @@ export type HttpAnyAgent = HTTPAgent | HTTPSAgent;
  * Returns a custom request Agent if one is found, otherwise returns undefined
  * which will result in the global http(s) Agent being used.
  * @private
- * @param {string} uri The request uri
+ * @param {string|undefined} uri The request uri
  * @param {Options} reqOpts The request options
  * @returns {HttpAnyAgent|undefined}
  */