diff --git a/nginx/snippets/security-headers.conf b/nginx/snippets/security-headers.conf
index 4110c9f..c0a7198 100644
--- a/nginx/snippets/security-headers.conf
+++ b/nginx/snippets/security-headers.conf
@@ -3,3 +3,6 @@ add_header X-Content-Type-Options "nosniff" always;
 
 # obsolete when client system time is correct
 add_header Expect-CT "enforce, max-age=63072000" always;
+
+# obsolete and replaced with strong Content-Security-Policy
+add_header X-XSS-Protection "1; mode=block" always;