diff --git a/auto-boot-ollama-pc.sh b/auto-boot-ollama-pc.sh
index 40b2766..daf7a2c 100755
--- a/auto-boot-ollama-pc.sh
+++ b/auto-boot-ollama-pc.sh
@@ -1,6 +1,9 @@
 #!/bin/bash
 set -euo pipefail
-SCRIPTNAME=$(basename "$(readlink -f "$0")")
+
+SCRIPT_PATH="$(readlink -f "$0" 2>/dev/null || realpath "$0" 2>/dev/null || echo "$0")"
+SCRIPTNAME="$(basename "$SCRIPT_PATH")"
+LOCKFILE="/var/lock/${SCRIPTNAME}.pid"
 
 # ========= Configuration =========
 CONTAINER_NAME="paperless-ai"
@@ -8,29 +11,49 @@ OLLAMA_HOST="192.168.222.12"
 OLLAMA_PORT="11434"
 ERROR_PATTERN="Error: \[ERROR\] Document analysis failed: connect EHOSTUNREACH $OLLAMA_HOST:$OLLAMA_PORT"
 
-
 # Tools (adjust if your distro uses different names)
 WOL_CMD="wakeonlan"                               # or "etherwake -i eth0 $WOL_MAC"
 NC_CMD="nc"                                       # netcat
 DOCKER="docker"
 
-sleep 1
+log() { printf '[%(%F %T)T] %s\n' -1 "$*"; }
 
-# Ensure only one instance of this script is running
-if [ "$(pgrep -f $SCRIPTNAME)" != $$ ]; then
-  echo "Killing running instance of $SCRIPTNAME..."
-  pgrep -f -- "$SCRIPTNAME" | grep -vw "$$" | xargs -r kill -KILL
+# --- Single-instance using PID lockfile in /var/lock ---
+# Read old PID (if any) and terminate that instance if it is our script.
+if [[ -f "$LOCKFILE" ]]; then
+  oldpid="$(cat "$LOCKFILE" 2>/dev/null || true)"
+  if [[ "${oldpid:-}" =~ ^[0-9]+$ ]] && kill -0 "$oldpid" 2>/dev/null; then
+    # Optional sanity check: ensure the old PID is this same script (best-effort).
+    if grep -qa "$SCRIPTNAME" "/proc/$oldpid/cmdline" 2>/dev/null; then
+      log "Found running instance (pid=$oldpid) → terminating"
+      kill "$oldpid" 2>/dev/null || true
+      # Give it a short grace period, then force if still alive.
+      for _ in 1 2 3; do
+        sleep 1
+        kill -0 "$oldpid" 2>/dev/null || break
+      done
+      kill -KILL "$oldpid" 2>/dev/null || true
+    fi
+  fi
 fi
 
-log() { printf '[%(%F %T)T] %s\n' -1 "$*"; }
+# Write our own PID to the lockfile (best-effort atomic via temp + move).
+tmp_lock="${LOCKFILE}.$$"
+printf '%d\n' "$$" > "$tmp_lock"
+mv -f "$tmp_lock" "$LOCKFILE"
 
-${DOCKER} logs -f --since 0s "${CONTAINER_NAME}" 2>&1 | \
-while IFS= read -r line; do
-  # Print lines optionally for debugging:
-  #echo "$line"
+# Clean up lockfile on exit.
+cleanup() {
+  [[ -f "$LOCKFILE" ]] && [[ "$(cat "$LOCKFILE" 2>/dev/null || true)" == "$$" ]] && rm -f "$LOCKFILE" || true
+}
+trap cleanup EXIT INT TERM
 
-  if echo "$line" | grep -qE "${ERROR_PATTERN}"; then
+# Follow container logs and look for the error pattern
+"$DOCKER" logs -f --since 0s "$CONTAINER_NAME" 2>&1 | \
+while IFS= read -r line; do
+  # echo "$line"   # uncomment for debugging
+  if echo "$line" | grep -qE "$ERROR_PATTERN"; then
     log "Detected EHOSTUNREACH for Ollama (${OLLAMA_HOST}:${OLLAMA_PORT})."
   fi
-
 done
+