diff --git a/files/en-us/web/http/csp/index.md b/files/en-us/web/http/csp/index.md
index 798183c1b126b1a..53582d01dc40633 100644
--- a/files/en-us/web/http/csp/index.md
+++ b/files/en-us/web/http/csp/index.md
@@ -431,7 +431,7 @@ The syntax of `frame-ancestors` is a subset of the fetch directive syntax: you c
 Unless you need your site to be embeddable, you should set `frame-ancestors` to `'none'`:
 
 ```plain
-frame-ancestors 'none'
+Content-Security-Policy: frame-ancestors 'none'
 ```
 
 This directive is a more flexible replacement for the {{httpheader("X-Frame-Options")}} header.