diff --git a/lib/ssh.c b/lib/ssh.c
index 9f676b8e31907e5620e51f242f937d80e261cabf..f56013ca71bd92b8d1db33cee9dd0045aa00505d 100644
--- a/lib/ssh.c
+++ b/lib/ssh.c
@@ -130,6 +130,14 @@
 #include "memdebug.h"
 #endif
 
+#ifndef S_IRGRP
+#define S_IRGRP  0
+#endif
+
+#ifndef S_IROTH
+#define S_IROTH 0
+#endif
+
 static LIBSSH2_ALLOC_FUNC(libssh2_malloc);
 static LIBSSH2_REALLOC_FUNC(libssh2_realloc);
 static LIBSSH2_FREE_FUNC(libssh2_free);