Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -1420,10 +1420,24 @@
 	esac
 
 	AC_CHECK_HEADER(sys/socket.h, [
 		AC_DEFINE(OF_HAVE_SYS_SOCKET_H, 1,
 			[Whether we have sys/socket.h])
+	])
+	AC_CHECK_MEMBER([struct sockaddr_storage.ss_family], [
+		AC_DEFINE(OF_HAVE_SOCKADDR_STORAGE, 1,
+			[Whether we have struct sockaddr_storage])
+	], [], [
+		#ifdef OF_HAVE_SYS_TYPES_H
+		# include <sys/types.h>
+		#endif
+		#ifdef OF_HAVE_SYS_SOCKET_H
+		# include <sys/socket.h>
+		#endif
+		#ifdef _WIN32
+		# include <winsock2.h>
+		#endif
 	])
 
 	AC_CHECK_HEADER(netinet/in.h, [
 		AC_DEFINE(OF_HAVE_NETINET_IN_H, 1,
 			[Whether we have netinet/in.h])

Index: src/OFSocket.h
==================================================================
--- src/OFSocket.h
+++ src/OFSocket.h
@@ -185,10 +185,17 @@
 		struct sockaddr_in in;
 		struct sockaddr_in6 in6;
 		struct sockaddr_un un;
 		struct sockaddr_ipx ipx;
 		struct sockaddr_at at;
+#ifdef OF_HAVE_SOCKADDR_STORAGE
+		/*
+		 * Required to make the ABI stable in case we want to add more
+		 * address types later.
+		 */
+		struct sockaddr_storage storage;
+#endif
 	} sockaddr;
 	socklen_t length;
 } OFSocketAddress;
 
 #ifdef __cplusplus

Index: src/objfw-defs.h.in
==================================================================
--- src/objfw-defs.h.in
+++ src/objfw-defs.h.in
@@ -32,10 +32,11 @@
 #undef OF_HAVE_PLUGINS
 #undef OF_HAVE_PTHREADS
 #undef OF_HAVE_PTHREAD_SPINLOCKS
 #undef OF_HAVE_RECURSIVE_PTHREAD_MUTEXES
 #undef OF_HAVE_SCHED_YIELD
+#undef OF_HAVE_SOCKADDR_STORAGE
 #undef OF_HAVE_SOCKETS
 #undef OF_HAVE_STDNORETURN
 #undef OF_HAVE_SUBPROCESSES
 #undef OF_HAVE_SYMLINK
 #undef OF_HAVE_SYNC_BUILTINS