diff --git a/net-proxy/squid/metadata.xml b/net-proxy/squid/metadata.xml
index f180385..8293f88 100644
--- a/net-proxy/squid/metadata.xml
+++ b/net-proxy/squid/metadata.xml
@@ -7,6 +7,8 @@
     <flag name="epoll">Enables Linux epoll() support</flag>
     <flag name="ecap">Adds support for loadable content adaptation modules
 		(http://www.e-cap.org)</flag>
+    <flag name="esi">Enable ESI for accelerators, will cause squid reverse proxies
+		to be capable of the Edge Acceleration Specification (www.esi.org)</flag>
 	<flag name="htcp">Enable HTCP protocol</flag>
     <flag name="icap-client">Adds ICAP client support</flag>
     <flag name="ipf-transparent">Adds transparent proxy support for systems
diff --git a/net-proxy/squid/squid-3.4.3.ebuild b/net-proxy/squid/squid-3.4.3.ebuild
index 10b260a..a5412bd 100644
--- a/net-proxy/squid/squid-3.4.3.ebuild
+++ b/net-proxy/squid/squid-3.4.3.ebuild
@@ -14,7 +14,7 @@ LICENSE="GPL-2"
 SLOT="0"
 KEYWORDS="~alpha ~amd64 ~arm ~hppa ~ia64 ~mips ~ppc ~ppc64 ~sparc ~x86 ~x86-fbsd"
 IUSE="caps ipv6 pam ldap samba sasl kerberos nis radius ssl snmp selinux logrotate test \
-	ecap icap-client ssl-crtd \
+	ecap esi icap-client ssl-crtd \
 	mysql postgres sqlite \
 	qos tproxy \
 	+htcp +wccp +wccpv2 \
@@ -29,6 +29,7 @@ COMMON_DEPEND="caps? ( >=sys-libs/libcap-2.16 )
 	ssl? ( dev-libs/openssl )
 	sasl? ( dev-libs/cyrus-sasl )
 	ecap? ( net-libs/libecap:0.2 )
+	esi? ( dev-libs/expat dev-libs/libxml2 )
 	selinux? ( sec-policy/selinux-squid )
 	!x86-fbsd? ( logrotate? ( app-admin/logrotate ) )
 	>=sys-libs/db-4
@@ -187,6 +188,7 @@ src_configure() {
 		$(use_enable ssl-crtd) \
 		$(use_enable icap-client) \
 		$(use_enable ecap) \
+		$(use_enable esi) \
 		$(use_enable htcp) \
 		$(use_enable wccp) \
 		$(use_enable wccpv2) \