diff --git a/seahub/auth/middleware.py b/seahub/auth/middleware.py
index 97ed01a338..b5dc7957ce 100644
--- a/seahub/auth/middleware.py
+++ b/seahub/auth/middleware.py
@@ -25,7 +25,6 @@ class LazyUser(object):
 
 
 class AuthenticationMiddleware(MiddlewareMixin):
-    async_mode = False
     def process_request(self, request):
         assert hasattr(
             request, 'session'
diff --git a/seahub/base/middleware.py b/seahub/base/middleware.py
index 931395bc1f..420f9e0301 100644
--- a/seahub/base/middleware.py
+++ b/seahub/base/middleware.py
@@ -34,7 +34,6 @@ class BaseMiddleware(MiddlewareMixin):
     """
     Middleware that add organization, group info to user.
     """
-    async_mode = False
     def process_request(self, request):
 
         username = request.user.username
@@ -84,7 +83,6 @@ class BaseMiddleware(MiddlewareMixin):
 
 class InfobarMiddleware(MiddlewareMixin):
     """Query info bar close status, and store into request."""
-    async_mode = False
     def get_from_db(self):
         ret = Notification.objects.all().filter(primary=1)
         refresh_cache()
@@ -119,7 +117,6 @@ class InfobarMiddleware(MiddlewareMixin):
 
 
 class ForcePasswdChangeMiddleware(MiddlewareMixin):
-    async_mode = False
     def _request_in_black_list(self, request):
         path = request.path
         black_list = (r'^%s$' % SITE_ROOT, r'home/.+', r'repo/.+',
@@ -165,9 +162,9 @@ class UserAgentMiddleWare(MiddlewareMixin):
     user_agents_android_search = u"(?:android)"
     user_agents_mobile_search = u"(?:mobile)"
     user_agents_tablets_search = u"(?:%s)" % u'|'.join(('ipad', 'tablet', ))
-    async_mode = False
 
     def __init__(self, get_response=None):
+        super().__init__(UserAgentMiddleWare)
         self.get_response = get_response
 
         # these for detect mobile
diff --git a/seahub/password_session/middleware.py b/seahub/password_session/middleware.py
index ad5faf6b34..4063c027b1 100644
--- a/seahub/password_session/middleware.py
+++ b/seahub/password_session/middleware.py
@@ -7,7 +7,6 @@ from .handlers import get_password_hash, PASSWORD_HASH_KEY
 
 class CheckPasswordHash(MiddlewareMixin):
     """Logout user if value of hash key in session is not equal to current password hash"""
-    async_mode = False
     def process_view(self, request, *args, **kwargs):
         if getattr(request.user, 'is_authenticated') and request.user.is_authenticated:
             if request.user.enc_password == '!':
diff --git a/seahub/trusted_ip/middleware.py b/seahub/trusted_ip/middleware.py
index bbf349d919..b0fa4470a3 100644
--- a/seahub/trusted_ip/middleware.py
+++ b/seahub/trusted_ip/middleware.py
@@ -11,7 +11,6 @@ from seahub.settings import ENABLE_LIMIT_IPADDRESS, TRUSTED_IP_LIST
 
 
 class LimitIpMiddleware(MiddlewareMixin):
-    async_mode = False
     def process_request(self, request):
         if not ENABLE_LIMIT_IPADDRESS:
             return None
diff --git a/seahub/two_factor/middleware.py b/seahub/two_factor/middleware.py
index c3649ae2fd..d23567fc58 100644
--- a/seahub/two_factor/middleware.py
+++ b/seahub/two_factor/middleware.py
@@ -33,7 +33,6 @@ class OTPMiddleware(MiddlewareMixin):
     verified.  As a convenience, this also installs ``user.is_verified()``,
     which returns ``True`` if ``user.otp_device`` is not ``None``.
     """
-    async_mode = False
     def process_request(self, request):
         if not config.ENABLE_TWO_FACTOR_AUTH:
             return None
diff --git a/thirdpart/termsandconditions/middleware.py b/thirdpart/termsandconditions/middleware.py
index 36ced61077..be3dad71a4 100644
--- a/thirdpart/termsandconditions/middleware.py
+++ b/thirdpart/termsandconditions/middleware.py
@@ -19,7 +19,6 @@ class TermsAndConditionsRedirectMiddleware(MiddlewareMixin):
     This middleware checks to see if the user is logged in, and if so,
     if they have accepted the site terms.
     """
-    async_mode = False
     def process_request(self, request):
         """Process each request to app to ensure terms have been accepted"""
         if not config.ENABLE_TERMS_AND_CONDITIONS: