diff --git a/src/win/tty.c b/src/win/tty.c
index 9b963778..59a991c6 100644
--- a/src/win/tty.c
+++ b/src/win/tty.c
@@ -40,6 +40,9 @@
 #include "stream-inl.h"
 #include "req-inl.h"
 
+#ifndef InterlockedOr
+# define InterlockedOr _InterlockedOr
+#endif
 
 #define UNICODE_REPLACEMENT_CHARACTER (0xfffd)