diff --git a/trove/common/db/mysql/models.py b/trove/common/db/mysql/models.py
index cf9d0fbf03..50700b103d 100644
--- a/trove/common/db/mysql/models.py
+++ b/trove/common/db/mysql/models.py
@@ -145,8 +145,8 @@ class MySQLUser(models.DatastoreUser):
         if CONF.hostname_require_valid_ip:
             try:
                 # '%' works as a MySQL wildcard, but it is not a valid
-                # part of an IPAddress
-                netaddr.IPAddress(value.replace('%', '1'))
+                # part of an IPNetwork
+                netaddr.IPNetwork(value.replace('%', '1'))
             except (ValueError, netaddr.AddrFormatError):
                 return False
             else:
diff --git a/trove/tests/unittests/guestagent/test_mysql_manager.py b/trove/tests/unittests/guestagent/test_mysql_manager.py
index 2f60dd05dd..1355420a61 100644
--- a/trove/tests/unittests/guestagent/test_mysql_manager.py
+++ b/trove/tests/unittests/guestagent/test_mysql_manager.py
@@ -20,6 +20,7 @@ from mock import patch
 from proboscis.asserts import assert_equal
 from testtools.matchers import Is, Equals, Not
 
+from trove.common.db.mysql import models
 from trove.common.exception import InsufficientSpaceForReplica
 from trove.common.exception import ProcessExecutionError
 from trove.common import instance as rd_instance
@@ -103,6 +104,15 @@ class GuestAgentManagerTest(DatastoreManagerTest):
         dbaas.MySqlAppStatus.get.assert_any_call()
         mock_status.update.assert_any_call()
 
+    def _empty_user(self):
+        return models.MySQLUser(deserializing=True)
+
+    def test_valid_host_name(self):
+        test_host = "192.58.197.0/255.255.255.0"
+        user = self._empty_user()
+        user.host = test_host
+        self.assertEqual(test_host, user.host)
+
     @patch.object(dbaas.MySqlAdmin, 'create_database')
     def test_create_database(self, create_db_mock):
         self.manager.create_database(self.context, ['db1'])