diff --git a/extensions/Makefile.in b/extensions/Makefile.in
index f885143f..defab61e 100644
--- a/extensions/Makefile.in
+++ b/extensions/Makefile.in
@@ -46,6 +46,7 @@ SRCS =                          \
   extb_account.c		\
   extb_canjoin.c		\
   extb_channel.c		\
+  extb_hostmask.c		\
   extb_oper.c			\
   extb_server.c			\
   extb_ssl.c			\
diff --git a/extensions/extb_hostmask.c b/extensions/extb_hostmask.c
new file mode 100644
index 00000000..bd513ea7
--- /dev/null
+++ b/extensions/extb_hostmask.c
@@ -0,0 +1,69 @@
+/*
+ * Hostmask extban type: bans all users matching a given hostmask, used for stacked extbans
+ * -- kaniini
+ */
+
+#include "stdinc.h"
+#include "modules.h"
+#include "client.h"
+#include "ircd.h"
+#include "ipv4_from_ipv6.h"
+
+static int _modinit(void);
+static void _moddeinit(void);
+static int eb_hostmask(const char *data, struct Client *client_p, struct Channel *chptr, long mode_type);
+
+DECLARE_MODULE_AV1(extb_hostmask, _modinit, _moddeinit, NULL, NULL, NULL, "$Revision: 1299 $");
+
+static int
+_modinit(void)
+{
+	extban_table['m'] = eb_hostmask;
+	return 0;
+}
+
+static void
+_moddeinit(void)
+{
+	extban_table['m'] = NULL;
+}
+
+static int
+eb_hostmask(const char *banstr, struct Client *client_p, struct Channel *chptr, long mode_type)
+{
+	char src_host[NICKLEN + USERLEN + HOSTLEN + 6];
+	char src_iphost[NICKLEN + USERLEN + HOSTLEN + 6];
+	char src_althost[NICKLEN + USERLEN + HOSTLEN + 6];
+	char src_ip4host[NICKLEN + USERLEN + HOSTLEN + 6];
+	struct sockaddr_in ip4;
+	char *s = src_host, *s2 = src_iphost, *s3 = NULL, *s4 = NULL;
+
+	rb_sprintf(src_host, "%s!%s@%s", client_p->name, client_p->username, client_p->host);
+	rb_sprintf(src_iphost, "%s!%s@%s", client_p->name, client_p->username, client_p->sockhost);
+
+	/* handle hostmangling if necessary */
+	if (client_p->localClient->mangledhost != NULL)
+	{
+		if (!strcmp(client_p->host, client_p->localClient->mangledhost))
+			rb_sprintf(src_althost, "%s!%s@%s", client_p->name, client_p->username, client_p->orighost);
+		else if (!IsDynSpoof(client_p))
+			rb_sprintf(src_althost, "%s!%s@%s", client_p->name, client_p->username, client_p->localClient->mangledhost);
+
+		s3 = src_althost;
+	}
+
+#ifdef RB_IPV6
+	/* handle Teredo if necessary */
+	if (client_p->localClient->ip.ss_family == AF_INET6 && ipv4_from_ipv6((const struct sockaddr_in6 *) &client_p->localClient->ip, &ip4))
+	{
+		rb_sprintf(src_ip4host, "%s!%s@", client_p->name, client_p->username);
+		s4 = src_ip4host + strlen(src_ip4host);
+		rb_inet_ntop_sock((struct sockaddr *)&ip4,
+				s4, src_ip4host + sizeof src_ip4host - s4);
+		s4 = src_ip4host;
+	}
+#endif
+
+	return match(banstr, s) || match(banstr, s2) || (s3 != NULL && match(banstr, s3)) || (s4 != NULL && match(banstr, s4)) ? EXTBAN_MATCH : EXTBAN_NOMATCH;
+}
+