diff --git a/rally/benchmark/scenarios/keystone/basic.py b/rally/benchmark/scenarios/keystone/basic.py
index c895cc3406..a5e49b9e4a 100644
--- a/rally/benchmark/scenarios/keystone/basic.py
+++ b/rally/benchmark/scenarios/keystone/basic.py
@@ -16,6 +16,7 @@
 from rally.benchmark.context import cleaner as context_cleaner
 from rally.benchmark.scenarios import base
 from rally.benchmark.scenarios.keystone import utils as kutils
+from rally.benchmark import validation as valid
 
 
 class KeystoneBasic(kutils.KeystoneScenario):
@@ -36,9 +37,10 @@ class KeystoneBasic(kutils.KeystoneScenario):
         self._tenant_create(name_length=name_length, **kwargs)
 
     @base.scenario(admin_only=True)
+    @valid.add_validator(valid.required_parameters(['users_per_tenant']))
     @context_cleaner.cleanup([])
-    def create_tenant_with_users(self, name_length=10,
-                                 users_per_tenant=10, **kwargs):
+    def create_tenant_with_users(self, users_per_tenant, name_length=10,
+                                 **kwargs):
         tenant = self._tenant_create(name_length=name_length, **kwargs)
-        self._users_create(tenant, name_length=name_length,
-                           users_per_tenant=users_per_tenant, **kwargs)
+        self._users_create(tenant, users_per_tenant, name_length=name_length,
+                           **kwargs)
diff --git a/rally/benchmark/scenarios/keystone/utils.py b/rally/benchmark/scenarios/keystone/utils.py
index 4511b243bc..554129897b 100644
--- a/rally/benchmark/scenarios/keystone/utils.py
+++ b/rally/benchmark/scenarios/keystone/utils.py
@@ -74,11 +74,11 @@ class KeystoneScenario(base.Scenario):
         return self.admin_clients("keystone").tenants.create(name, **kwargs)
 
     @scenario_utils.atomic_action_timer('keystone.create_users')
-    def _users_create(self, tenant, name_length=10, users_per_tenant=10):
+    def _users_create(self, tenant, users_per_tenant, name_length=10):
         """Adds users to a tenant.
 
-        :param name_length: length of generated (random) part of name for user
         :param users_per_tenant: number of users in per tenant
+        :param name_length: length of generated (random) part of name for user
         """
         for i in range(users_per_tenant):
             name = generate_keystone_name(length=name_length)
diff --git a/rally/benchmark/validation.py b/rally/benchmark/validation.py
index 950408979e..d94c3ef3d3 100644
--- a/rally/benchmark/validation.py
+++ b/rally/benchmark/validation.py
@@ -130,3 +130,18 @@ def image_valid_on_flavor(flavor_name, image_name):
 
         return ValidationResult()
     return image_valid_on_flavor_validator
+
+
+def required_parameters(params):
+    """Returns validator for required parameters
+
+    :param params: list of required parameters
+    """
+    def required_parameters_validator(**kwargs):
+        missing = set(params) - set(kwargs)
+        if missing:
+            message = _("%s parameters are not defined in "
+                        "the benchmark config file") % ", ".join(missing)
+            return ValidationResult(False, message)
+        return ValidationResult()
+    return required_parameters_validator
diff --git a/tests/benchmark/scenarios/keystone/test_utils.py b/tests/benchmark/scenarios/keystone/test_utils.py
index 3a69ba3421..4e383e7722 100644
--- a/tests/benchmark/scenarios/keystone/test_utils.py
+++ b/tests/benchmark/scenarios/keystone/test_utils.py
@@ -115,7 +115,7 @@ class KeystoneScenarioTestCase(test.TestCase):
         fake_clients._keystone = fake_keystone
         scenario = utils.KeystoneScenario(admin_clients=fake_clients)
 
-        scenario._users_create(tenant, 10, 1)
+        scenario._users_create(tenant, users_per_tenant=1, name_length=10)
 
         fake_keystone.users.create.assert_called_once_with(name, name,
                                                            name + "@rally.me",