diff --git a/devstack/lib/l2_agent b/devstack/lib/l2_agent
index b70efb1d4a4..0e7b8401072 100644
--- a/devstack/lib/l2_agent
+++ b/devstack/lib/l2_agent
@@ -9,5 +9,5 @@ function plugin_agent_add_l2_agent_extension {
 
 
 function configure_l2_agent {
-    iniset /$Q_PLUGIN_CONF_FILE agent extensions "$L2_AGENT_EXTENSIONS"
+    iniset /$NEUTRON_CORE_PLUGIN_CONF agent extensions "$L2_AGENT_EXTENSIONS"
 }
diff --git a/devstack/lib/l2_agent_sriovnicswitch b/devstack/lib/l2_agent_sriovnicswitch
index f422773b0a8..f6cc63f91dc 100755
--- a/devstack/lib/l2_agent_sriovnicswitch
+++ b/devstack/lib/l2_agent_sriovnicswitch
@@ -1,4 +1,4 @@
-SRIOV_AGENT_CONF="${Q_PLUGIN_CONF_PATH}/sriov_agent.ini"
+SRIOV_AGENT_CONF="${NEUTRON_CORE_PLUGIN_CONF_PATH}/sriov_agent.ini"
 SRIOV_AGENT_BINARY="${NEUTRON_BIN_DIR}/neutron-sriov-nic-agent"
 
 function configure_l2_agent_sriovnicswitch {
diff --git a/devstack/lib/macvtap_agent b/devstack/lib/macvtap_agent
index 60ed687a86c..bdaf2131f7c 100644
--- a/devstack/lib/macvtap_agent
+++ b/devstack/lib/macvtap_agent
@@ -33,7 +33,7 @@ function neutron_plugin_configure_l3_agent {
 function neutron_plugin_configure_plugin_agent {
     # Only the NooPFirewallDriver is supported. If not set, the agent will
     # terminate.
-    iniset /$Q_PLUGIN_CONF_FILE securitygroup firewall_driver noop
+    iniset /$NEUTRON_CORE_PLUGIN_CONF securitygroup firewall_driver noop
     AGENT_BINARY="$NEUTRON_BIN_DIR/neutron-macvtap-agent"
 }
 
diff --git a/devstack/lib/qos b/devstack/lib/qos
index e9270c04321..a033c908a73 100644
--- a/devstack/lib/qos
+++ b/devstack/lib/qos
@@ -4,7 +4,7 @@ function configure_qos_service_plugin {
 
 
 function configure_qos_core_plugin {
-    configure_qos_$Q_PLUGIN
+    configure_qos_$NEUTRON_CORE_PLUGIN
 }
 
 
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index 7791c624149..0cb2a8a9e34 100644
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -1,5 +1,12 @@
 LIBDIR=$DEST/neutron/devstack/lib
 
+if is_neutron_legacy_enabled; then
+    NEUTRON_CORE_PLUGIN=$Q_PLUGIN
+    NEUTRON_AGENT=$Q_AGENT
+    NEUTRON_CORE_PLUGIN_CONF_PATH=$Q_PLUGIN_CONF_PATH
+    NEUTRON_CORE_PLUGIN_CONF=$Q_PLUGIN_CONF_FILE
+fi
+
 source $LIBDIR/dns
 source $LIBDIR/flavors
 source $LIBDIR/l2_agent
@@ -11,8 +18,8 @@ source $LIBDIR/trunk
 
 Q_BUILD_OVS_FROM_GIT=$(trueorfalse False Q_BUILD_OVS_FROM_GIT)
 
-if [ -f $LIBDIR/${Q_AGENT}_agent ]; then
-    source $LIBDIR/${Q_AGENT}_agent
+if [ -f $LIBDIR/${NEUTRON_AGENT}_agent ]; then
+    source $LIBDIR/${NEUTRON_AGENT}_agent
 fi
 
 if [[ "$1" == "stack" ]]; then
@@ -30,7 +37,7 @@ if [[ "$1" == "stack" ]]; then
             if is_service_enabled q-dns; then
                 configure_dns_extension
             fi
-            if [[ "$Q_AGENT" == "openvswitch" ]] && \
+            if [[ "$NEUTRON_AGENT" == "openvswitch" ]] && \
                [[ "$Q_BUILD_OVS_FROM_GIT" == "True" ]]; then
                 remove_ovs_packages
                 compile_ovs True /usr /var
@@ -50,7 +57,7 @@ if [[ "$1" == "stack" ]]; then
             #Therefore we create new service, q-sriov-agt, and the q-agt should be OVS
             #or linux bridge.
             if is_service_enabled q-sriov-agt; then
-                configure_$Q_PLUGIN
+                configure_$NEUTRON_CORE_PLUGIN
                 configure_l2_agent
                 configure_l2_agent_sriovnicswitch
             fi
diff --git a/neutron/tests/contrib/hooks/mtu b/neutron/tests/contrib/hooks/mtu
index aa52e64b882..f72a86573eb 100644
--- a/neutron/tests/contrib/hooks/mtu
+++ b/neutron/tests/contrib/hooks/mtu
@@ -3,7 +3,7 @@
 [neutron_plugin_options]
 available_type_drivers=flat,geneve,vlan,gre,local,vxlan
 
-[[post-config|/$Q_PLUGIN_CONF_FILE]]
+[[post-config|/$NEUTRON_CORE_PLUGIN_CONF]]
 
 [ml2]
 type_drivers=flat,geneve,vlan,gre,local,vxlan
diff --git a/neutron/tests/contrib/hooks/ovsfw b/neutron/tests/contrib/hooks/ovsfw
index 20147b3d2a7..b9faa1d6433 100644
--- a/neutron/tests/contrib/hooks/ovsfw
+++ b/neutron/tests/contrib/hooks/ovsfw
@@ -1,4 +1,4 @@
-[[post-config|/$Q_PLUGIN_CONF_FILE]]
+[[post-config|/$NEUTRON_CORE_PLUGIN_CONF]]
 
 [securitygroup]
 firewall_driver = openvswitch