diff --git a/srcpkgs/firefox/template b/srcpkgs/firefox/template
index a59ab41f821..1c03fd2204c 100644
--- a/srcpkgs/firefox/template
+++ b/srcpkgs/firefox/template
@@ -10,14 +10,17 @@ distfiles="${MOZILLA_SITE}/${pkgname}/releases/${version}/source/${pkgname}-${ve
 checksum=994a346699298277b64ec0cab72660b8d3e5b879a2ac79207576f7e6c33da3ae
 
 lib32disabled=yes
+build_options="gtk3"
+desc_option_gtk3="Build the GTK+3 toolkit UI"
 
 hostmakedepends="unzip zip pkg-config perl python yasm"
-makedepends="nss-devel libjpeg-turbo-devel libpng-devel
- icu55-devel pixman-devel sqlite-devel gst-plugins-base1-devel gtk+-devel
+makedepends="
+ nss-devel libjpeg-turbo-devel libpng-devel gtk+-devel
+ icu55-devel pixman-devel sqlite-devel gst-plugins-base1-devel
  libevent-devel libnotify-devel libvpx-devel libXrender-devel
  startup-notification-devel dbus-glib-devel alsa-lib-devel pulseaudio-devel
  hunspell-devel libXcomposite-devel libSM-devel libXScrnSaver-devel
- libXt-devel libXdamage-devel"
+ libXt-devel libXdamage-devel $(vopt_if gtk3 gtk+3-devel)"
 depends="nss>=3.20.1 desktop-file-utils hicolor-icon-theme"
 conflicts="firefox-esr>=0"
 
@@ -39,19 +42,19 @@ pre_configure() {
 	[ ! -d xbps-build ] && mkdir -p xbps-build
 }
 do_configure() {
-	local cross_args
+	local _args
 
 	case "$XBPS_TARGET_MACHINE" in
 	*-musl) # XXX gold linking with --hash-style=sysv results in unhidden symbols
 		# XXX see https://sourceware.org/ml/binutils/2014-09/msg00230.html
 		#
 		# XXX disable jemalloc.
-		cross_args+=" --disable-jemalloc --enable-gold=no"
+		_args+=" --disable-jemalloc --enable-gold=no"
 		;;
 	esac
 
 	if [ "$CROSS_BUILD" ]; then
-		cross_args+=" --target=$XBPS_CROSS_TRIPLET --disable-jemalloc"
+		_args+=" --target=$XBPS_CROSS_TRIPLET --disable-jemalloc"
 
 		# Make config/system_wrappers/alsa/alsalib.h and pulse/pulse.h find
 		# the required includes. Set system nspr and nss include paths.
@@ -75,6 +78,12 @@ do_configure() {
 	mkdir -p /usr/lib/firefox
 	export LDFLAGS+=" -Wl,-rpath=/usr/lib/firefox"
 
+	if [ "$build_option_gtk3" ]; then
+		_args+=" --enable-default-toolkit=cairo-gtk3"
+	else
+		_args+=" --enable-default-toolkit=cairo-gtk2"
+	fi
+
 	cd xbps-build
 	# XXX build without --system-cairo. See:
 	# - https://github.com/voidlinux/void-packages/issues/2308#issuecomment-135426813
@@ -92,11 +101,11 @@ do_configure() {
 		--with-system-icu --enable-pulseaudio --enable-gstreamer=1.0 \
 		--disable-crashreporter --disable-cpp-exceptions --disable-javaxpcom \
 		--with-nspr-prefix=${XBPS_CROSS_BASE}/usr \
-		--with-nss-prefix=${XBPS_CROSS_BASE}/usr ${cross_args} \
+		--with-nss-prefix=${XBPS_CROSS_BASE}/usr \
 		--with-google-api-keyfile="${wrksrc}/google-api-key" \
 		--enable-optimize="$CFLAGS" --disable-strip --disable-install-strip \
-		--disable-static --enable-pie \
-		--disable-profiling --disable-profilelocking
+		--disable-static --enable-pie --disable-profiling \
+		--disable-profilelocking ${_args}
 }
 do_build() {
 	cd xbps-build