diff --git a/compat.h b/compat.h
index c52f80b7..c4404c86 100644
--- a/compat.h
+++ b/compat.h
@@ -14,6 +14,29 @@
 
 #include <windows.h>
 
+
+#if !defined S_ISDIR && defined S_IFDIR
+# define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
+#endif
+#if !S_IRUSR && S_IREAD
+# define S_IRUSR S_IREAD
+#endif
+#if !S_IRUSR
+# define S_IRUSR 00400
+#endif
+#if !S_IWUSR && S_IWRITE
+# define S_IWUSR S_IWRITE
+#endif
+#if !S_IWUSR
+# define S_IWUSR 00200
+#endif
+#if !S_IXUSR && S_IEXEC
+# define S_IXUSR S_IEXEC
+#endif
+#if !S_IXUSR
+# define S_IXUSR 00100
+#endif
+
 #ifndef HAVE_LIBWINPTHREAD
 static inline int nanosleep(const struct timespec *req, struct timespec *rem)
 {