Index: Mk/bsd.gecko.mk
===================================================================
--- Mk/bsd.gecko.mk	(revision 562767)
+++ Mk/bsd.gecko.mk	(working copy)
@@ -240,6 +240,10 @@
 MOZ_OPTIONS+=	--disable-libproxy
 .endif
 
+.if ${PORT_OPTIONS:MLTO}
+MOZ_OPTIONS+=	--enable-lto=cross
+.endif
+
 .if ${PORT_OPTIONS:MALSA}
 BUILD_DEPENDS+=	${LOCALBASE}/include/alsa/asoundlib.h:audio/alsa-lib
 MOZ_OPTIONS+=	--enable-alsa
Index: www/firefox/Makefile.options
===================================================================
--- www/firefox/Makefile.options	(revision 562767)
+++ www/firefox/Makefile.options	(working copy)
@@ -1,7 +1,7 @@
 # -*- makefile-bsdmake -*-
 
 OPTIONS_DEFINE+= 	CANBERRA DBUS DEBUG FFMPEG \
-			LIBPROXY OPTIMIZED_CFLAGS PROFILE TEST
+			LIBPROXY LTO OPTIMIZED_CFLAGS PROFILE TEST
 
 OPTIONS_DEFAULT+=	DBUS FFMPEG OPTIMIZED_CFLAGS PROFILE \
 			${OPTIONS_GROUP_AUDIO:NALSA}
@@ -13,3 +13,4 @@
 CANBERRA_DESC?=		Sound theme alerts
 LIBPROXY_DESC?=		Proxy support via libproxy
 LIGHTNING_DESC?=	Calendar extension
+LTO_DESC?=		Link-time optimization