diff --git a/ProcessWin32.c b/ProcessWin32.c
index 4de4bad5c6972b94ad1f51f0e8e0517ccc1305a5..8255f5278eb23236327451333650b95d9b2723a0 100644
--- a/ProcessWin32.c
+++ b/ProcessWin32.c
@@ -40,6 +40,14 @@ Q190351 and Q150956.
 #include <string.h>  /* strlen, strdup */
 #include <stdio.h>   /* sprintf */
 #include <io.h>      /* _unlink */
+
+#ifndef _MAX_FNAME
+#define _MAX_FNAME 4096
+#endif
+#ifndef _MAX_PATH
+#define _MAX_PATH 4096
+#endif
+
 #ifdef _MSC_VER
 #pragma warning (pop)
 #pragma warning (disable: 4514)