diff --git a/lib/mockResponse.js b/lib/mockResponse.js
index 72216a4..38aa53b 100644
--- a/lib/mockResponse.js
+++ b/lib/mockResponse.js
@@ -636,7 +636,7 @@ function createResponse(options = {}) {
      *
      *   Append a header by name. If a header already exists, the new value is appended to the existing header.
      */
-    mockResponse.appendHeader = function setHeader(name, value) {
+    mockResponse.appendHeader = function appendHeader(name, value) {
         mockResponse.append(name, value);
         return this;
     };