diff --git a/qse/configure b/qse/configure
index fff06df5..f52fa4bf 100755
--- a/qse/configure
+++ b/qse/configure
@@ -18780,6 +18780,7 @@ _ACEOF
 fi
 
 
+
 ac_fn_c_check_member "$LINENO" "struct ifreq" "ifr_ifindex" "ac_cv_member_struct_ifreq_ifr_ifindex" "#include <sys/types.h>
 	 #include <sys/socket.h>
 	 #ifdef HAVE_NET_IF_H
@@ -18854,6 +18855,20 @@ _ACEOF
 fi
 
 
+ac_fn_c_check_member "$LINENO" "struct sockaddr_in6" "sin6_scope_id" "ac_cv_member_struct_sockaddr_in6_sin6_scope_id" "#include <sys/types.h>
+	 #include <sys/socket.h>
+	 #include <netinet/in.h>
+"
+if test "x$ac_cv_member_struct_sockaddr_in6_sin6_scope_id" = xyes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID 1
+_ACEOF
+
+
+fi
+
+
 # The cast to long int works around a bug in the HP C Compiler
 # version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
 # declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
diff --git a/qse/configure.ac b/qse/configure.ac
index d9fb9185..aa8ed696 100644
--- a/qse/configure.ac
+++ b/qse/configure.ac
@@ -281,6 +281,7 @@ AC_CHECK_MEMBERS([struct stat.st_birthtim.tv_nsec])
 AC_CHECK_MEMBERS([struct stat.st_mtimespec.tv_nsec])
 AC_CHECK_MEMBERS([struct stat.st_birthtimespec.tv_nsec])
 
+
 AC_CHECK_MEMBERS([struct ifreq.ifr_ifindex, struct ifreq.ifr_mtu], [], [],
 	[#include <sys/types.h>
 	 #include <sys/socket.h>
@@ -295,6 +296,11 @@ AC_CHECK_TYPES([struct lifconf, struct lifreq, struct if_laddrreq], [], [],
 	 #include <net/if.h>
 	 #endif])
 
+AC_CHECK_MEMBERS([struct sockaddr_in6.sin6_scope_id], [], [],
+	[#include <sys/types.h> 
+	 #include <sys/socket.h> 
+	 #include <netinet/in.h>])
+
 dnl check the size of primitive data types
 AC_CHECK_SIZEOF(char,,[[]])
 AC_CHECK_SIZEOF(short,,[[]])
diff --git a/qse/include/qse/config.h.in b/qse/include/qse/config.h.in
index 2afdfbdb..ece6d26e 100644
--- a/qse/include/qse/config.h.in
+++ b/qse/include/qse/config.h.in
@@ -428,6 +428,9 @@
 /* Define to 1 if the system has the type `struct lifreq'. */
 #undef HAVE_STRUCT_LIFREQ
 
+/* Define to 1 if `sin6_scope_id' is a member of `struct sockaddr_in6'. */
+#undef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID
+
 /* Define to 1 if `st_birthtime' is a member of `struct stat'. */
 #undef HAVE_STRUCT_STAT_ST_BIRTHTIME
 
diff --git a/qse/lib/cmn/nwad-skad.c b/qse/lib/cmn/nwad-skad.c
index ecc55612..3ab3b0e6 100644
--- a/qse/lib/cmn/nwad-skad.c
+++ b/qse/lib/cmn/nwad-skad.c
@@ -95,7 +95,9 @@ static QSE_INLINE int skad_to_nwad (const sockaddr_t* skad, qse_nwad_t* nwad)
 			QSE_MEMSET (nwad, 0, QSE_SIZEOF(*nwad));
 			nwad->type = QSE_NWAD_IN6;
 			QSE_MEMCPY (&nwad->u.in6.addr, &in->sin6_addr, QSE_SIZEOF(nwad->u.in6.addr));
+		#if defined(HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID)
 			nwad->u.in6.scope = in->sin6_scope_id;
+		#endif
 			nwad->u.in6.port = in->sin6_port;
 			break;
 		}
@@ -141,7 +143,9 @@ static QSE_INLINE int nwad_to_skad (const qse_nwad_t* nwad, sockaddr_t* skad)
 
 			in->sin6_family = AF_INET6;
 			QSE_MEMCPY (&in->sin6_addr, &nwad->u.in6.addr, QSE_SIZEOF(nwad->u.in6.addr));
+		#if defined(HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID)
 			in->sin6_scope_id = nwad->u.in6.scope;
+		#endif
 			in->sin6_port = nwad->u.in6.port;
 #endif
 			break;