diff --git a/seafile-11.0_ubuntu b/seafile-11.0_ubuntu
index 61e1268..f422547 100644
--- a/seafile-11.0_ubuntu
+++ b/seafile-11.0_ubuntu
@@ -152,7 +152,7 @@ fi
 apt-get update
 
 apt-get install -y python3 python3-dev python3-setuptools python3-pip python3-ldap memcached \
-    libmemcached-dev pwgen curl nginx libmysqlclient-dev ldap-utils libldap2-dev
+    libmemcached-dev pwgen curl nginx libmysqlclient-dev ldap-utils libldap2-dev dnsutils
 
 pip3 install --timeout=3600 django==3.2.* future==0.18.* mysqlclient==2.1.* pymysql pillow==10.0.* pylibmc captcha==0.4 markupsafe==2.0.1 jinja2 sqlalchemy==2.0.18 psd-tools django-pylibmc django_simple_captcha==0.5.* djangosaml2==1.5.* pysaml2==7.2.* pycryptodome==3.16.* cffi==1.15.1 python-ldap==3.4.3 lxml \
   -i https://pypi.tuna.tsinghua.edu.cn/simple/