diff --git a/ares/ares_process.c b/ares/ares_process.c
index 4a88b76a8efc4e8969ced33f7083c67c5e205145..19fe0828929b89074c1e7da32ed518213561ff2b 100644
--- a/ares/ares_process.c
+++ b/ares/ares_process.c
@@ -42,7 +42,7 @@
 #include "ares_dns.h"
 #include "ares_private.h"
 
-#if defined(WIN32) || defined(WATT32)
+#if (defined(WIN32) || defined(WATT32)) && !defined(MSDOS)
 #define GET_ERRNO()  WSAGetLastError()
 #else
 #define GET_ERRNO()  errno