diff --git a/manifests/network/controller.pp b/manifests/network/controller.pp
index def77b9d..092b960c 100644
--- a/manifests/network/controller.pp
+++ b/manifests/network/controller.pp
@@ -150,6 +150,12 @@
 #   List of colon-separated id ranges
 #   Defautls to ['1:10000']
 #
+# [*mechanism_drivers*]
+#   (optional) Neutron mechanism drivers to run
+#   List of drivers.
+#   Note: if l3-ha is True, do not include l2population (not compatible in Juno).
+#   Defaults to ['linuxbridge', 'openvswitch','l2population']
+#
 class cloud::network::controller(
   $neutron_db_host         = '127.0.0.1',
   $neutron_db_user         = 'neutron',
@@ -174,6 +180,7 @@ class cloud::network::controller(
   $type_drivers            = ['gre', 'vlan', 'flat'],
   $provider_vlan_ranges    = ['physnet1:1000:2999'],
   $plugin                  = 'ml2',
+  $mechanism_drivers       = ['linuxbridge', 'openvswitch','l2population'],
   $l3_ha                   = false,
   $router_distributed      = false,
   # only needed by cisco n1kv plugin
@@ -194,6 +201,11 @@ class cloud::network::controller(
     fail 'l3_ha and router_distributed are mutually exclusive, only one of them can be set to true'
   }
 
+  validate_array($mechanism_drivers)
+  if $l3_ha and member($mechanism_drivers, 'l2population') {
+    fail 'l3_ha does not work with l2population mechanism driver in Juno.'
+  }
+
   class { 'neutron::server':
     auth_password       => $ks_neutron_password,
     auth_host           => $ks_keystone_admin_host,
@@ -217,7 +229,7 @@ class cloud::network::controller(
         tunnel_id_ranges      => $tunnel_id_ranges,
         vni_ranges            => $vni_ranges,
         flat_networks         => $flat_networks,
-        mechanism_drivers     => ['linuxbridge', 'openvswitch','l2population'],
+        mechanism_drivers     => $mechanism_drivers,
         enable_security_group => true
       }
     }
diff --git a/spec/classes/cloud_network_controller_spec.rb b/spec/classes/cloud_network_controller_spec.rb
index 741a319c..bc7f0b50 100644
--- a/spec/classes/cloud_network_controller_spec.rb
+++ b/spec/classes/cloud_network_controller_spec.rb
@@ -174,7 +174,8 @@ describe 'cloud::network::controller' do
 
     context 'with L3 HA' do
       before :each do
-        params.merge!(:l3_ha => true)
+        params.merge!(:l3_ha             => true,
+                      :mechanism_drivers => ['openvswitch'])
       end
       it 'should configure L3 HA' do
         is_expected.to contain_class('neutron::server').with(
@@ -217,6 +218,14 @@ describe 'cloud::network::controller' do
       end
       it_raises 'a Puppet::Error', /l3_ha and router_distributed are mutually exclusive, only one of them can be set to true/
     end
+
+    context 'with L3 HA and l2population enabled' do
+      before :each do
+        params.merge!(:l3_ha             => true,
+                      :mechanism_drivers => ['openvswitch', 'l2population'])
+      end
+      it_raises 'a Puppet::Error', /l3_ha does not work with l2population mechanism driver in Juno./
+    end
   end
 
   context 'on Debian platforms' do