Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -1403,11 +1403,11 @@
 	])
 	AC_CHECK_HEADER(netinet/tcp.h, [
 		AC_DEFINE(OF_HAVE_NETINET_TCP_H, 1,
 			[Whether we have netinet/tcp.h])
 	])
-	AC_CHECK_HEADERS([arpa/inet.h netdb.h])
+	AC_CHECK_HEADERS([arpa/inet.h netdb.h net/if.h])
 	AC_CHECK_HEADER(sys/un.h, [
 		AC_DEFINE(OF_HAVE_SYS_UN_H, 1, [Whether we have sys/un.h])
 	])
 	AC_CHECK_MEMBER([struct sockaddr_in6.sin6_addr], [
 		AC_EGREP_CPP(egrep_cpp_yes, [

Index: src/OFSocket.m
==================================================================
--- src/OFSocket.m
+++ src/OFSocket.m
@@ -23,10 +23,14 @@
 #ifdef OF_NINTENDO_3DS
 # include <malloc.h>  /* For memalign() */
 #endif
 
 #include <errno.h>
+
+#ifdef HAVE_NET_IF_H
+# include <net/if.h>
+#endif
 
 #import "OFArray.h"
 #import "OFCharacterSet.h"
 #import "OFLocale.h"
 #ifdef OF_HAVE_THREADS
@@ -45,10 +49,16 @@
 #import "OFInvalidArgumentException.h"
 #import "OFInvalidFormatException.h"
 #import "OFLockFailedException.h"
 #import "OFOutOfRangeException.h"
 #import "OFUnlockFailedException.h"
+
+#ifdef OF_WINDOWS
+# define interface struct
+# include <netioapi.h>
+# undef interface
+#endif
 
 #ifdef OF_AMIGAOS
 # include <proto/exec.h>
 #endif
 
@@ -431,11 +441,11 @@
 OFSocketAddressParseIPv6(OFString *IPv6, uint16_t port)
 {
 	void *pool = objc_autoreleasePoolPush();
 	OFSocketAddress ret;
 	struct sockaddr_in6 *addrIn6 = &ret.sockaddr.in6;
-	size_t doubleColon;
+	size_t doubleColon, percent;
 
 	memset(&ret, '\0', sizeof(ret));
 	ret.family = OFSocketAddressFamilyIPv6;
 	ret.length = sizeof(ret.sockaddr.in6);
 
@@ -443,13 +453,20 @@
 	addrIn6->sin6_family = AF_INET6;
 #else
 	addrIn6->sin6_family = AF_UNSPEC;
 #endif
 	addrIn6->sin6_port = OFToBigEndian16(port);
+
+	if ((percent = [IPv6 rangeOfString: @"%"].location) != OFNotFound) {
+		OFString *interface = [IPv6 substringFromIndex: percent + 1];
+		IPv6 = [IPv6 substringToIndex: percent];
+
+		addrIn6->sin6_scope_id = if_nametoindex(
+		    [interface cStringWithEncoding: [OFLocale encoding]]);
+	}
 
 	doubleColon = [IPv6 rangeOfString: @"::"].location;
-
 	if (doubleColon != OFNotFound) {
 		OFString *left = [IPv6 substringToIndex: doubleColon];
 		OFString *right = [IPv6 substringFromIndex: doubleColon + 2];
 		OFArray OF_GENERIC(OFString *) *leftComponents;
 		OFArray OF_GENERIC(OFString *) *rightComponents;
@@ -867,10 +884,19 @@
 			    (addrIn6->sin6_addr.s6_addr[i] << 8) |
 			    addrIn6->sin6_addr.s6_addr[i + 1]];
 			first = false;
 		}
 	}
+
+	if (addrIn6->sin6_scope_id != 0) {
+		char interface[IF_NAMESIZE];
+
+		if (if_indextoname(addrIn6->sin6_scope_id, interface) != NULL)
+			[string appendFormat: @"%%%s", interface];
+		else
+			[string appendFormat: @"%%%u", addrIn6->sin6_scope_id];
+	}
 
 	[string makeImmutable];
 
 	return string;
 }