diff --git a/.includes/toggle-screen.sh b/.includes/toggle-screen.sh
index bdf9992..7f8d4bd 100755
--- a/.includes/toggle-screen.sh
+++ b/.includes/toggle-screen.sh
@@ -2,17 +2,42 @@
 
 # Change between dummy and fbdev driver for X session.
 
+sudoFlags=()
+if [[ -n "${SUDO_ASKPASS:-}" ]]; then
+    sudoFlags=("-A")
+fi
+
+xorgConfDir="/etc/X11/xorg.conf.d"
+xorgConfFile="${xorgConfDir}/10-screendriver.conf"
+
+ensure_xorg_conf_dir() {
+    if ! sudo "${sudoFlags[@]}" mkdir -p "${xorgConfDir}"; then
+        msgbox "Failed to create ${xorgConfDir}."
+        return 1
+    fi
+}
+
 active_screen() {
-    cat << EOF | sudo "${sudoFlags[@]}" tee /etc/X11/xorg.conf.d/10-screendriver.conf &> /dev/null
+    if ! ensure_xorg_conf_dir; then
+        return 1
+    fi
+    if ! sudo "${sudoFlags[@]}" tee "${xorgConfFile}" > /dev/null << 'EOF'
 Section "Device"
     Identifier  "FBdev"
     Driver      "fbdev"
 EndSection
 EOF
+    then
+        msgbox "Failed to write ${xorgConfFile}."
+        return 1
+    fi
 }
 
 headless() {
-    cat << EOF | sudo "${sudoFlags[@]}" tee /etc/X11/xorg.conf.d/10-screendriver.conf &> /dev/null
+    if ! ensure_xorg_conf_dir; then
+        return 1
+    fi
+    if ! sudo "${sudoFlags[@]}" tee "${xorgConfFile}" > /dev/null << 'EOF'
 Section "Monitor"
     Identifier "dummy_monitor"
     HorizSync 28.0-80.0
@@ -42,6 +67,10 @@ Section "ServerLayout"
     Screen 0 "dummy_screen"
 EndSection
 EOF
+    then
+        msgbox "Failed to write ${xorgConfFile}."
+        return 1
+    fi
 }
 
 
@@ -49,11 +78,17 @@ source ./.includes/functions.sh
 source ./.includes/ui.sh
 answer=$(yesno "Do you have a physical screen attached?")
 if [[ "${answer}" == "Yes" ]]; then
-    active_screen
-    msgbox "Settings for physical screen applied."
+    if active_screen; then
+        msgbox "Settings for physical screen applied."
+    else
+        exit 1
+    fi
 else
-    headless
-    msgbox "Settings for no screen applied."
+    if headless; then
+        msgbox "Settings for no screen applied."
+    else
+        exit 1
+    fi
 fi
 
 if [[ "$1" != "-n" ]]; then