diff --git a/ares/Makefile.netware b/ares/Makefile.netware
index 5ce895786..c522de3cb 100644
--- a/ares/Makefile.netware
+++ b/ares/Makefile.netware
@@ -297,6 +297,7 @@ config.h: Makefile.netware
 	@echo $(DL)#define SIZEOF_CURL_OFF_T 4$(DL) >> $@
 	@echo $(DL)#define STDC_HEADERS 1$(DL) >> $@
 	@echo $(DL)#define TIME_WITH_SYS_TIME 1$(DL) >> $@
+	@echo $(DL)#define HAVE_STRUCT_IN6_ADDR 1$(DL) >> $@
 ifdef NW_WINSOCK
 	@echo $(DL)#define HAVE_CLOSESOCKET 1$(DL) >> $@
 else