diff --git a/types/html-validator/index.d.ts b/types/html-validator/index.d.ts
index d180c4db52..c6961bdced 100644
--- a/types/html-validator/index.d.ts
+++ b/types/html-validator/index.d.ts
@@ -24,6 +24,7 @@ declare namespace HtmlValidator {
         ignore?: string | string[];
         isLocal?: boolean;
         isFragment?: boolean;
+        headers?: Record<string, string>;
     }
 
     interface OptionsForHtmlFileAsValidationTarget extends BasicOptions {