diff --git a/libmysql/manager.c b/libmysql/manager.c
index f1fa73dbcd1..33b2b643333 100644
--- a/libmysql/manager.c
+++ b/libmysql/manager.c
@@ -55,7 +55,9 @@
 #endif
 
 #define RES_BUF_SHIFT 5
+#ifndef __WIN__
 #define SOCKET_ERROR -1
+#endif
 #define NET_BUF_SIZE  2048
 
 MYSQL_MANAGER*  STDCALL mysql_manager_init(MYSQL_MANAGER* con)