diff --git a/test/ares-test-internal.cc b/test/ares-test-internal.cc
index e9a024492..96d4edece 100644
--- a/test/ares-test-internal.cc
+++ b/test/ares-test-internal.cc
@@ -578,7 +578,7 @@ const struct ares_socket_functions VirtualizeIO::default_functions = {
 #endif
   },
   [](ares_socket_t s, const struct iovec * vec, int len, void *) {
-#ifdef _WIN32
+#ifndef HAVE_WRITEV
     return ares_writev(s, vec, len);
 #else
     return :: writev(s, vec, len);