diff --git a/format-test.cc b/format-test.cc
index e71c58fd..42ef65fb 100644
--- a/format-test.cc
+++ b/format-test.cc
@@ -52,6 +52,10 @@
 #  define O_CREAT _O_CREAT
 #  define S_IRUSR _S_IREAD
 #  define S_IWUSR _S_IWRITE
+#  define open _open
+#  define close _close
+#  define dup _dup
+#  define dup2 _dup2
 # else
 #  include <unistd.h>
 # endif