diff --git a/scripts/seafile-monitor.sh b/scripts/seafile-monitor.sh
index 708ddee212..27ab416b8d 100755
--- a/scripts/seafile-monitor.sh
+++ b/scripts/seafile-monitor.sh
@@ -54,7 +54,7 @@ ENABLE_NOTIFICATION_SERVER=`awk -F '=' '/\[notification\]/{a=1}a==1&&$1~/^enable
 log "Start Monitor"
 
 while [ 1 ]; do
-    if [ $ENABLE_NOTIFICATION_SERVER = "true" ]; then
+    if [ $ENABLE_NOTIFICATION_SERVER ] && [ $ENABLE_NOTIFICATION_SERVER = "true" ]; then
         monitor_notification_server
     fi
 
diff --git a/scripts/seafile.sh b/scripts/seafile.sh
index 9d9cd9a01a..bdcf834746 100755
--- a/scripts/seafile.sh
+++ b/scripts/seafile.sh
@@ -154,7 +154,7 @@ function start_seafile_server () {
 
     # notification-sever
     ENABLE_NOTIFICATION_SERVER=`awk -F '=' '/\[notification\]/{a=1}a==1&&$1~/^enabled/{print $2;exit}' ${central_config_dir}/seafile.conf`
-    if [ $ENABLE_NOTIFICATION_SERVER == "true" ]; then
+    if [ $ENABLE_NOTIFICATION_SERVER ] && [ $ENABLE_NOTIFICATION_SERVER = "true" ]; then
         notification-server -c ${central_config_dir} -l ${TOPDIR}/logs/notification-server.log &
         ${INSTALLPATH}/seafile-monitor.sh &>> ${TOPDIR}/logs/seafile-monitor.log &
     fi