--- a/chrome/browser/webauthn/authenticator_request_dialog_model.h
+++ b/chrome/browser/webauthn/authenticator_request_dialog_model.h
@@ -9,6 +9,7 @@
 #include <optional>
 #include <string>
 #include <string_view>
+#include <variant>
 #include <vector>
 
 #include "base/containers/span.h"
