diff --git a/debian/postinst b/debian/postinst
index 44b28d1..2dcaf56 100755
--- a/debian/postinst
+++ b/debian/postinst
@@ -24,7 +24,7 @@ chmod -R 750 /var/lib/mond
 
 # Create configuration file if it doesn't exist
 if [ ! -f /var/lib/mond/params.conf ]; then
-    cat > /var/lib/mond/params.conf << 'EOF'
+    cat > /var/lib/mond/params.conf << 'CONF'
 # Mond Configuration File
 # This file is automatically created during installation
 # Edit this file to customize your Mond daemon settings
@@ -116,7 +116,7 @@ log-level=1
 
 # log-file: 日志文件保存路径
 log-file=/var/log/mond/mond.log
-EOF
+CONF
     chown mond:mond /var/lib/mond/params.conf
     chmod 640 /var/lib/mond/params.conf
 fi
@@ -125,11 +125,19 @@ fi
 chown root:mond /opt/mond/mond
 chmod 755 /opt/mond/mond
 
-# Reload systemd
+# Reload systemd and handle service restart on upgrade
 if [ -d /run/systemd/system ]; then
     systemctl daemon-reload
 
-    # Note: Service is NOT auto-enabled or auto-started
+    # On upgrade: restart service if it was enabled
+    if [ "$1" = "configure" ] && [ -n "$2" ]; then
+        # $2 is the previously installed version (only set on upgrade)
+        if systemctl is-enabled --quiet mond.service 2>/dev/null; then
+            echo "Restarting mond service after upgrade..."
+            systemctl start mond.service || true
+        fi
+    fi
+    # Note: On fresh install, service is NOT auto-enabled or auto-started
     # Users should manually enable the service:
     #   systemctl enable mond.service
     #   systemctl start mond.service
diff --git a/debian/prerm b/debian/prerm
index ef25451..fa0289b 100755
--- a/debian/prerm
+++ b/debian/prerm
@@ -1,17 +1,36 @@
 #!/bin/sh
 set -e
 
-# Stop and disable service if running
-if [ -d /run/systemd/system ]; then
-    if systemctl is-active --quiet mond.service; then
-        echo "Stopping mond service..."
-        systemctl stop mond.service
-    fi
-
-    if systemctl is-enabled --quiet mond.service 2>/dev/null; then
-        echo "Disabling mond service..."
-        systemctl disable mond.service
-    fi
-fi
+case "$1" in
+    upgrade)
+        # 升级时只停止服务，保留 enabled 状态
+        if [ -d /run/systemd/system ]; then
+            if systemctl is-active --quiet mond.service; then
+                echo "Stopping mond service for upgrade..."
+                systemctl stop mond.service
+            fi
+        fi
+        ;;
+    remove|deconfigure)
+        # 删除时停止并禁用服务
+        if [ -d /run/systemd/system ]; then
+            if systemctl is-active --quiet mond.service; then
+                echo "Stopping mond service..."
+                systemctl stop mond.service
+            fi
+            if systemctl is-enabled --quiet mond.service 2>/dev/null; then
+                echo "Disabling mond service..."
+                systemctl disable mond.service
+            fi
+        fi
+        ;;
+    failed-upgrade)
+        # 升级失败时不做操作
+        ;;
+    *)
+        echo "prerm called with unknown argument \`$1'" >&2
+        exit 1
+        ;;
+esac
 
 exit 0