diff --git a/test/posix-test.cc b/test/posix-test.cc
index 7dd0dbb0..007e2507 100644
--- a/test/posix-test.cc
+++ b/test/posix-test.cc
@@ -31,7 +31,7 @@
 #include "posix.h"
 #include "util.h"
 
-#ifdef __MINGW32__
+#ifdef fileno
 # undef fileno
 #endif