diff --git a/installer/gentoo/prepare b/installer/gentoo/prepare
index 4978f50a5..9ba8e722b 100644
--- a/installer/gentoo/prepare
+++ b/installer/gentoo/prepare
@@ -88,6 +88,24 @@ By installing $3, the license $2 has been enabled.
 "
 }
 
+# Set a use expand flag
+# Usage: set_use_expand <variable to expand> <flag to enable>
+set_use_expand() {
+    # Check if the variable is already present
+    EXPAND=`grep "$1" /etc/portage/make.conf | cut -f2 -d\"`
+    # If not, add it with the desired flag
+    if [ -z "$EXPAND" ]; then
+        echo "$1=\"$2\"" >> /etc/portage/make.conf
+    # If the variable is already present, check if the flag is already set
+    else
+        FLAG_SET=`echo $EXPAND | grep $2 | cut -f1 -d\"`
+	# Add the flag
+	if [ -z "$FLAG_SET" ]; then
+            sed -i -e "s|$1=\"\(.*\)\"|$1=\"\1 $2\"|" /etc/portage/make.conf
+	fi
+    fi
+}
+
 # install_dist: see install() in prepare.sh for details.
 install_dist() {
     local pkgs=''
diff --git a/targets/xiwi b/targets/xiwi
index c2bec7093..b131cc492 100755
--- a/targets/xiwi
+++ b/targets/xiwi
@@ -29,17 +29,20 @@ if [ "${DISTROAKA:-"$DISTRO"}" = 'debian' ]; then
 fi
 
 if [ "${DISTROAKA:-"$DISTRO"}" = 'gentoo' ]; then
-    VIDEO_CARDS=`grep VIDEO_CARDS /etc/portage/make.conf | cut -d= -f1`
-    if [ -z ${VIDEO_CARDS} ]; then
-        echo "VIDEO_CARDS=\"dummy\"" >> /etc/portage/make.conf
-        echo "INPUT_DEVICES=\"keyboard libinput mouse evdev\"" >> /etc/portage/make.conf
-    fi
+    # Set video card and input devices
+    set_use_expand VIDEO_CARDS dummy
+    set_use_expand INPUT_DEVICES keyboard
+    set_use_expand INPUT_DEVICES libinput
+    set_use_expand INPUT_DEVICES mouse
+    set_use_expand INPUT_DEVICES evdev
     
+    # Set use flags for X
     set_flags X dbus
     # We remove the suid bit because it breaks LD_PRELOAD'ing libcroutonfreon.so
     set_package_flag x11-base/xorg-server -suid xorg
-
+    # Install xorg
     install xorg-x11 xorg-server
+    # Set the flags for i3 and install it
     set_flags xcb xkb
     install i3
 else
diff --git a/targets/xorg b/targets/xorg
index 80f25f2a3..ff946a57b 100644
--- a/targets/xorg
+++ b/targets/xorg
@@ -17,17 +17,17 @@ rm -f '/etc/crouton/xserverrc-x11'
 
 # Set the use flags on gentoo that we'll need for X
 if [ "${DISTROAKA:-"$DISTRO"}" = 'gentoo' ]; then
-    set_flags libkms uxa dri3 xvmc opengl -suid
-    # We remove the suid bit because it breaks LD_PRELOAD'ing libcroutonfreon.so
-    set_package_flag x11-base/xorg-server -suid xorg
-     
-     # Set VIDEO_CARDS and INPUT_DEVICES
-     # FIXME: Perhaps make this more flexible, right now just pick all of them
-     VIDEO_CARDS=`grep VIDEO_CARDS /etc/portage/make.conf | cut -d= -f1`
-     if [ -z ${VIDEO_CARDS} ]; then
-         echo "VIDEO_CARDS=\"intel fbdev vesa dummy\"" >> /etc/portage/make.conf
-         echo "INPUT_DEVICES=\"keyboard libinput mouse evdev\"" >> /etc/portage/make.conf
-     fi
+   set_flags libkms uxa dri3 xvmc opengl -suid
+   # We remove the suid bit because it breaks LD_PRELOAD'ing libcroutonfreon.so
+   set_package_flag x11-base/xorg-server -suid xorg
+   # Set video card and input devices
+   # FIXME: ARM, non-intel?
+   set_use_expand VIDEO_CARDS intel
+   set_use_expand INPUT_DEVICES keyboard
+   set_use_expand INPUT_DEVICES libinput
+   set_use_expand INPUT_DEVICES mouse
+   set_use_expand INPUT_DEVICES evdev
+   set_use_expand INPUT_DEVICES synaptics
 fi
 
 # Figure out what we need on this system