diff --git a/I38.md b/I38.md
index 0591a20..72c29de 100644
--- a/I38.md
+++ b/I38.md
@@ -184,6 +184,12 @@ If required dependencies are installed, you can use OCR to read text from images
 
 *GNOME/MATE comparison:* OCR features are typically not integrated into GNOME/MATE by default.
 
+### Screen Lock
+
+If you enabled the I38 privacy screen lock during setup, press `Control` + `Alt` + `Tab` to enter panel mode, then press `Control` + `MODKEY` + `l` to lock the screen. This is a privacy screen for I38, not a secure system lock.
+
+When a screen lock PIN is configured, I38 can also autolock after an idle timeout. The default is never. Autolock is X11/i3-only and requires `xprintidle`; if `playerctl` is installed, I38 will avoid autolocking during likely video playback.
+
 ### Sound Effects
 
 I38 provides audio feedback for many actions:
diff --git a/README.md b/README.md
index a8b6b6e..f46184e 100644
--- a/README.md
+++ b/README.md
@@ -34,6 +34,7 @@ An uppercase I looks like a 1, 3 from i3, and 8 because the song [We Are 138](ht
 scrot: For OCR
 - sox: for sounds.
 - tesseract: For OCR
+- xprintidle: [optional] For screen lock autolock on X11/i3
 - tesseract-data-eng: For OCR
 - udiskie: [optional] for automatically mounting removable storage
 - x11bell: [optional] Bell support if you do not have a PC speaker. Available from https://github.com/jovanlanik/x11bell
diff --git a/i38.sh b/i38.sh
index a45d765..96c2b95 100755
--- a/i38.sh
+++ b/i38.sh
@@ -220,6 +220,27 @@ select_personal_mode_key() {
     normalize_ratpoison_key "$selectedKey"
 }
 
+select_screenlock_autolock_seconds() {
+    local selectedAutolock
+
+    if ! selectedAutolock="$(dialog --title "I38" \
+        --backtitle "Use the arrow keys to choose how long I38 should wait before locking the screen automatically." \
+        --clear \
+        --default-item "0" \
+        --menu "Autolock screen after:" 0 0 0 \
+        "0" "Never" \
+        "180" "3 minutes" \
+        "300" "5 minutes" \
+        "600" "10 minutes" \
+        "1800" "30 minutes" \
+        "3600" "1 hour" \
+        --stdout)"; then
+        selectedAutolock="0"
+    fi
+
+    echo "$selectedAutolock"
+}
+
 update_personal_customizations() {
     local customizationsPath="${i3Path}/customizations"
     local startMarker="# I38 Personal mode start"
@@ -322,6 +343,7 @@ sounds="$sounds"
 
 # Screen lock
 screenlockPinHash="$screenlockPinHash"
+screenlockAutolockSeconds="${screenlockAutolockSeconds:-0}"
 
 # Personal mode
 personalModeEnabled="${personalModeEnabled:-0}"
@@ -799,6 +821,18 @@ if [[ -z "$screenlockPinHash" ]]; then
         done
     fi
 fi
+if [[ -n "$screenlockPinHash" ]]; then
+    if command -v xprintidle &> /dev/null; then
+        if [[ -z "${screenlockAutolockSeconds+x}" ]] || [[ ! "$screenlockAutolockSeconds" =~ ^[0-9]+$ ]]; then
+            configChanged=1
+            screenlockAutolockSeconds="$(select_screenlock_autolock_seconds)"
+        fi
+    elif [[ -z "${screenlockAutolockSeconds+x}" ]] || [[ ! "$screenlockAutolockSeconds" =~ ^[0-9]+$ ]]; then
+        screenlockAutolockSeconds=0
+    fi
+else
+    screenlockAutolockSeconds=0
+fi
 # Personal mode
 personalModeExists=1
 if personal_mode_exists; then
@@ -1257,6 +1291,9 @@ fi
 if [[ $batteryAlert -eq 0 ]]; then
     echo "exec_always --no-startup-id ${i3Path}/scripts/battery_alert.sh"
 fi
+if [[ $usingSway -ne 0 ]] && [[ -n "$screenlockPinHash" ]] && [[ "${screenlockAutolockSeconds:-0}" -gt 0 ]] && command -v xprintidle &> /dev/null; then
+    echo "exec_always --no-startup-id ${i3Path}/scripts/screenlock_autolock.sh ${screenlockAutolockSeconds}"
+fi
 # WayTray system tray daemon
 if command -v waytray-daemon &> /dev/null ; then
     echo 'exec_always --no-startup-id bash -c "pgrep -x waytray-daemon > /dev/null || waytray-daemon"'
@@ -1379,7 +1416,37 @@ while IFS= read -r line; do
 
         lastComment=""
     fi
-done < <(sed -n '/^mode "/,/^}$/!p' "${i3Path}/config" | grep -E '^#|^bindsym')
+done < <(
+    awk '
+        /^mode "/ {
+            inMode = 1
+            previousComment = ""
+            next
+        }
+        inMode && /^}$/ {
+            inMode = 0
+            next
+        }
+        inMode {
+            next
+        }
+        /^#/ {
+            previousComment = $0
+            next
+        }
+        /^bindsym/ {
+            if (previousComment != "") {
+                print previousComment
+                previousComment = ""
+            }
+            print
+            next
+        }
+        {
+            previousComment = ""
+        }
+    ' "${i3Path}/config"
+)
 
 # Build HTML tables
 {
diff --git a/scripts/screenlock_autolock.sh b/scripts/screenlock_autolock.sh
new file mode 100755
index 0000000..9c4039b
--- /dev/null
+++ b/scripts/screenlock_autolock.sh
@@ -0,0 +1,112 @@
+#!/usr/bin/env bash
+
+# This file is part of I38.
+
+# I38 is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation,
+# either version 3 of the License, or (at your option) any later version.
+
+# I38 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+# PURPOSE. See the GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License along with I38. If not, see <https://www.gnu.org/licenses/>.
+
+autolockSeconds="${1:-0}"
+scriptPath="$(readlink -f "$0")"
+scriptDir="${scriptPath%/*}"
+runtimeDir="${XDG_RUNTIME_DIR:-/tmp}"
+lockDir="${runtimeDir}/i38-screenlock-autolock"
+pollSeconds=5
+
+notify_autolock_disabled() {
+    local message="$1"
+
+    if command -v notify-send &> /dev/null; then
+        notify-send "I38 autolock disabled" "$message"
+    fi
+}
+
+video_is_playing() {
+    local playerStatus playerUrl
+
+    if ! command -v playerctl &> /dev/null; then
+        return 1
+    fi
+
+    while IFS='|' read -r _ playerStatus playerUrl; do
+        if [[ "$playerStatus" != "Playing" ]]; then
+            continue
+        fi
+
+        if [[ "$playerUrl" =~ \.(avi|flv|m4v|mkv|mov|mp4|mpeg|mpg|ogm|ogv|webm|wmv)(\?.*)?$ ]]; then
+            return 0
+        fi
+    done < <(playerctl -a metadata --format '{{playerName}}|{{status}}|{{xesam:url}}' 2> /dev/null || true)
+
+    return 1
+}
+
+focused_window_is_fullscreen() {
+    if ! command -v i3-msg &> /dev/null || ! command -v jq &> /dev/null; then
+        return 1
+    fi
+
+    i3-msg -t get_tree \
+        | jq -e 'any(.. | objects; (.focused? == true) and ((.fullscreen_mode? // 0) != 0))' \
+        &> /dev/null
+}
+
+screenlock_is_running() {
+    pgrep -f "${scriptDir}/screenlock.sh" &> /dev/null
+}
+
+cleanup() {
+    rm -rf "$lockDir"
+}
+
+stop_autolock() {
+    cleanup
+    exit 0
+}
+
+if [[ ! "$autolockSeconds" =~ ^[0-9]+$ ]] || [[ "$autolockSeconds" -le 0 ]]; then
+    exit 0
+fi
+
+if [[ -z "${DISPLAY:-}" ]]; then
+    notify_autolock_disabled "No X display was found."
+    exit 0
+fi
+
+if ! command -v xprintidle &> /dev/null; then
+    notify_autolock_disabled "Install xprintidle to use screen lock autolock."
+    exit 0
+fi
+
+if [[ -d "$lockDir" ]]; then
+    if [[ -f "${lockDir}/pid" ]]; then
+        read -r existingPid < "${lockDir}/pid"
+        if [[ "$existingPid" =~ ^[0-9]+$ ]] && kill -0 "$existingPid" 2> /dev/null; then
+            exit 0
+        fi
+    fi
+    rm -rf "$lockDir"
+fi
+
+if ! mkdir "$lockDir" 2> /dev/null; then
+    exit 0
+fi
+printf "%s\n" "$$" > "${lockDir}/pid"
+trap cleanup EXIT
+trap stop_autolock INT TERM
+
+while : ; do
+    idleMilliseconds="$(xprintidle 2> /dev/null || echo 0)"
+    if [[ "$idleMilliseconds" =~ ^[0-9]+$ ]] && [[ "$idleMilliseconds" -ge $((autolockSeconds * 1000)) ]]; then
+        if ! screenlock_is_running && ! video_is_playing && ! focused_window_is_fullscreen; then
+            "${scriptDir}/screenlock.sh"
+            sleep "$pollSeconds"
+        fi
+    fi
+
+    sleep "$pollSeconds"
+done