diff --git a/reference/network/functions/header-register-callback.xml b/reference/network/functions/header-register-callback.xml
index 06fd4eee66..da50e9855e 100644
--- a/reference/network/functions/header-register-callback.xml
+++ b/reference/network/functions/header-register-callback.xml
@@ -58,7 +58,7 @@ header('X-Test: foo');
 
 function foo() {
  foreach (headers_list() as $header) {
-   if (strpos($header, 'X-Powered') !== false) {
+   if (strpos($header, 'X-Powered-By:') !== false) {
      header_remove('X-Powered-By');
    }
    header_remove('X-Test');