--- cups-2.3.3_p2-r3.ebuild
+++ cups-2.4.0.ebuild
@@ -28,9 +28,8 @@
 
 LICENSE="Apache-2.0"
 SLOT="0"
-IUSE="acl dbus debug kerberos pam selinux +ssl static-libs systemd +threads usb X xinetd zeroconf"
+IUSE="acl dbus debug kerberos pam selinux +ssl static-libs systemd usb X xinetd zeroconf"
 
-REQUIRED_USE="usb? ( threads )"
 # upstream includes an interactive test which is a nono for gentoo
 RESTRICT="test"
 
@@ -67,14 +66,11 @@
 PDEPEND=">=net-print/cups-filters-1.0.43"
 
 PATCHES=(
-	"${FILESDIR}/${PN}-2.2.6-fix-install-perms.patch"
-	"${FILESDIR}/${PN}-1.4.4-nostrip.patch"
-	"${FILESDIR}/${PN}-2.3.3-user-AR.patch"
-	# Upstream patches (from Debian and Fedora)
-	"${FILESDIR}/${PN}-2.3.3-timeout.patch"
-	"${FILESDIR}/${PN}-2.3.3-enforcing-read-limits.patch"
-	"${FILESDIR}/${PN}-2.3.3-manpage.patch"
-	"${FILESDIR}/${PN}-2.3.3-ipp-retry-validate.patch"
+	"${FILESDIR}/${PN}-2.4_rc1-nostrip.patch"
+	"${FILESDIR}/${PN}-2.4_rc1-user-AR.patch"
+
+	# https://github.com/OpenPrinting/cups/issues/299
+	"${FILESDIR}/${P}-empty_webUI_de.patch"
 )
 
 MULTILIB_CHOST_TOOLS=(
@@ -169,12 +165,11 @@
 		$(use_enable kerberos gssapi)
 		$(multilib_native_use_enable pam)
 		$(use_enable static-libs static)
-		$(use_enable threads)
-		$(use_enable ssl gnutls)
-		$(use_enable systemd)
+		$(use_with ssl tls gnutls)
+		$(use_with systemd)
+		$(use_with systemd ondemand systemd)
 		$(multilib_native_use_enable usb libusb)
-		$(use_enable zeroconf avahi)
-		--disable-dnssd
+		$(use_enable zeroconf dnssd avahi)
 		$(multilib_is_native_abi && echo --enable-libpaper || echo --disable-libpaper)
 	)