diff --git a/net-mgmt/net-snmp/Makefile b/net-mgmt/net-snmp/Makefile
index cbd5b07fbb88..ebd6b6177af3 100644
--- a/net-mgmt/net-snmp/Makefile
+++ b/net-mgmt/net-snmp/Makefile
@@ -7,6 +7,7 @@
 
 PORTNAME=	snmp
 PORTVERSION=	5.7.2
+PORTREVISION=	1
 CATEGORIES=	net-mgmt ipv6
 MASTER_SITES=	SF/net-${PORTNAME}/net-${PORTNAME}/${PORTVERSION}
 PKGNAMEPREFIX=	net-
@@ -88,7 +89,7 @@ CONFIGURE_ARGS+=	--with-openssl="${OPENSSLBASE}"
 CONFIGURE_ARGS+=--with-dummy-values
 .endif
 
-.if empty(${PORT_OPTIONS:MTKMIB})
+.if empty(PORT_OPTIONS:MTKMIB)
 EXTRA_PATCHES+=	${PATCHDIR}/extra-patch-local:Makefile.in
 PLIST_SUB+=	WITH_TKMIB="@comment "
 .else
@@ -99,7 +100,7 @@ PLIST_SUB+=	WITH_TKMIB=""
 .if ${PORT_OPTIONS:MPERL}
 USE_PERL5=	yes
 CONFIGURE_ARGS+=--with-perl-modules
-.if empty(${PORT_OPTIONS:MPERL_EMBEDDED})
+.if empty(PORT_OPTIONS:MPERL_EMBEDDED)
 CONFIGURE_ARGS+=--disable-embedded-perl
 PLIST_SUB+=	WITH_PERL_EMBEDDED="@comment "
 .else
diff --git a/net-mgmt/net-snmp/files/patch-agent__mibgroup__agent__extend.c b/net-mgmt/net-snmp/files/patch-agent__mibgroup__agent__extend.c
new file mode 100644
index 000000000000..5f3fa960a1e3
--- /dev/null
+++ b/net-mgmt/net-snmp/files/patch-agent__mibgroup__agent__extend.c
@@ -0,0 +1,44 @@
+--- ./agent/mibgroup/agent/extend.c.orig	2012-10-09 18:28:58.000000000 -0400
++++ ./agent/mibgroup/agent/extend.c	2012-10-24 07:46:37.000000000 -0400
+@@ -34,7 +34,7 @@
+     size_t              oid_len;
+     long                num_entries;
+     netsnmp_extend     *ehead;
+-    netsnmp_handler_registration       *reg[3];
++    netsnmp_handler_registration       *reg[4];
+     struct extend_registration_block_s *next;
+ } extend_registration_block;
+ extend_registration_block *ereg_head = NULL;
+@@ -222,10 +222,13 @@
+     rc = netsnmp_register_watched_scalar2( reg, winfo );
+     if (rc != SNMPERR_SUCCESS)
+         goto bail;
++    eptr->reg[3] = reg;
+ 
+     return eptr;
+ 
+ bail:
++    if (eptr->reg[3])
++        netsnmp_unregister_handler(eptr->reg[3]);
+     if (eptr->reg[2])
+         netsnmp_unregister_handler(eptr->reg[2]);
+     if (eptr->reg[1])
+@@ -267,6 +270,7 @@
+         netsnmp_unregister_handler( eptr->reg[0] );
+         netsnmp_unregister_handler( eptr->reg[1] );
+         netsnmp_unregister_handler( eptr->reg[2] );
++        netsnmp_unregister_handler( eptr->reg[3] );
+         SNMP_FREE(eptr);
+     }
+     ereg_head = NULL;
+@@ -550,6 +554,10 @@
+     }
+ 
+     eptr      = _register_extend( oid_buf, oid_len );
++    if (!eptr) {
++        snmp_log(LOG_ERR, "Failed to register extend entry '%s' - possibly duplicate name.\n", exec_name );
++        return;
++    }
+     extension = _new_extension( exec_name, flags, eptr );
+     if (extension) {
+         extension->command  = strdup( exec_command );