diff --git a/changelog.d/3800.bugfix b/changelog.d/3800.bugfix
new file mode 100644
index 0000000000..6b2e18b4a6
--- /dev/null
+++ b/changelog.d/3800.bugfix
@@ -0,0 +1 @@
+guest users should not be part of mau total
diff --git a/synapse/storage/monthly_active_users.py b/synapse/storage/monthly_active_users.py
index c7899d7fd2..b890c152db 100644
--- a/synapse/storage/monthly_active_users.py
+++ b/synapse/storage/monthly_active_users.py
@@ -199,10 +199,14 @@ class MonthlyActiveUsersStore(SQLBaseStore):
         Args:
             user_id(str): the user_id to query
         """
+
         if self.hs.config.limit_usage_by_mau:
+            # Trial users and guests should not be included as part of MAU group
+            is_guest = yield self.is_guest(user_id)
+            if is_guest:
+                return
             is_trial = yield self.is_trial_user(user_id)
             if is_trial:
-                # we don't track trial users in the MAU table.
                 return
 
             last_seen_timestamp = yield self.user_last_seen_monthly_active(user_id)
diff --git a/tests/storage/test_client_ips.py b/tests/storage/test_client_ips.py
index c2e88bdbaf..c9b02a062b 100644
--- a/tests/storage/test_client_ips.py
+++ b/tests/storage/test_client_ips.py
@@ -101,13 +101,11 @@ class ClientIpStoreTestCase(tests.unittest.TestCase):
         self.hs.config.limit_usage_by_mau = True
         self.hs.config.max_mau_value = 50
         user_id = "@user:server"
+        yield self.store.register(user_id=user_id, token="123", password_hash=None)
 
         active = yield self.store.user_last_seen_monthly_active(user_id)
         self.assertFalse(active)
 
-        yield self.store.insert_client_ip(
-            user_id, "access_token", "ip", "user_agent", "device_id"
-        )
         yield self.store.insert_client_ip(
             user_id, "access_token", "ip", "user_agent", "device_id"
         )
diff --git a/tests/storage/test_monthly_active_users.py b/tests/storage/test_monthly_active_users.py
index 2036287288..ccfc21b7fc 100644
--- a/tests/storage/test_monthly_active_users.py
+++ b/tests/storage/test_monthly_active_users.py
@@ -12,6 +12,9 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from mock import Mock
+
+from twisted.internet import defer
 
 from tests.unittest import HomeserverTestCase
 
@@ -23,7 +26,8 @@ class MonthlyActiveUsersTestCase(HomeserverTestCase):
 
         hs = self.setup_test_homeserver()
         self.store = hs.get_datastore()
-
+        hs.config.limit_usage_by_mau = True
+        hs.config.max_mau_value = 50
         # Advance the clock a bit
         reactor.advance(FORTY_DAYS)
 
@@ -73,7 +77,7 @@ class MonthlyActiveUsersTestCase(HomeserverTestCase):
         active_count = self.store.get_monthly_active_count()
         self.assertEquals(self.get_success(active_count), user_num)
 
-        # Test that regalar users are removed from the db
+        # Test that regular users are removed from the db
         ru_count = 2
         self.store.upsert_monthly_active_user("@ru1:server")
         self.store.upsert_monthly_active_user("@ru2:server")
@@ -139,3 +143,43 @@ class MonthlyActiveUsersTestCase(HomeserverTestCase):
 
         count = self.store.get_monthly_active_count()
         self.assertEquals(self.get_success(count), 0)
+
+    def test_populate_monthly_users_is_guest(self):
+        # Test that guest users are not added to mau list
+        user_id = "user_id"
+        self.store.register(
+            user_id=user_id, token="123", password_hash=None, make_guest=True
+        )
+        self.store.upsert_monthly_active_user = Mock()
+        self.store.populate_monthly_active_users(user_id)
+        self.pump()
+        self.store.upsert_monthly_active_user.assert_not_called()
+
+    def test_populate_monthly_users_should_update(self):
+        self.store.upsert_monthly_active_user = Mock()
+
+        self.store.is_trial_user = Mock(
+            return_value=defer.succeed(False)
+        )
+
+        self.store.user_last_seen_monthly_active = Mock(
+            return_value=defer.succeed(None)
+        )
+        self.store.populate_monthly_active_users('user_id')
+        self.pump()
+        self.store.upsert_monthly_active_user.assert_called_once()
+
+    def test_populate_monthly_users_should_not_update(self):
+        self.store.upsert_monthly_active_user = Mock()
+
+        self.store.is_trial_user = Mock(
+            return_value=defer.succeed(False)
+        )
+        self.store.user_last_seen_monthly_active = Mock(
+            return_value=defer.succeed(
+                self.hs.get_clock().time_msec()
+            )
+        )
+        self.store.populate_monthly_active_users('user_id')
+        self.pump()
+        self.store.upsert_monthly_active_user.assert_not_called()
diff --git a/tests/utils.py b/tests/utils.py
index b85017d279..91173fa45d 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -147,6 +147,7 @@ def setup_test_homeserver(
         config.hs_disabled_message = ""
         config.hs_disabled_limit_type = ""
         config.max_mau_value = 50
+        config.mau_trial_days = 0
         config.mau_limits_reserved_threepids = []
         config.admin_contact = None
         config.rc_messages_per_second = 10000