diff --git a/lib/neutron_plugins/ml2 b/lib/neutron_plugins/ml2
index 6ac20fe72e..4469634c1b 100644
--- a/lib/neutron_plugins/ml2
+++ b/lib/neutron_plugins/ml2
@@ -10,9 +10,9 @@ set +o xtrace
 Q_ML2_TENANT_NETWORK_TYPE=${Q_ML2_TENANT_NETWORK_TYPE:-}
 # This has to be set here since the agent will set this in the config file
 if [[ "$Q_ML2_TENANT_NETWORK_TYPE" != "" ]]; then
-    Q_AGENT_EXTRA_AGENT_OPTS=(tunnel_types=$Q_ML2_TENANT_NETWORK_TYPE)
+    Q_AGENT_EXTRA_AGENT_OPTS+=(tunnel_types=$Q_ML2_TENANT_NETWORK_TYPE)
 elif [[ "$ENABLE_TENANT_TUNNELS" = "True" ]]; then
-    Q_AGENT_EXTRA_AGENT_OPTS=(tunnel_types=gre)
+    Q_AGENT_EXTRA_AGENT_OPTS+=(tunnel_types=gre)
 fi
 
 # Default openvswitch L2 agent
@@ -50,14 +50,14 @@ function neutron_plugin_configure_common() {
 
 function neutron_plugin_configure_service() {
     if [[ "$Q_ML2_TENANT_NETWORK_TYPE" != "" ]]; then
-        Q_SRV_EXTRA_OPTS=(tenant_network_types=$Q_ML2_TENANT_NETWORK_TYPE)
+        Q_SRV_EXTRA_OPTS+=(tenant_network_types=$Q_ML2_TENANT_NETWORK_TYPE)
     elif [[ "$ENABLE_TENANT_TUNNELS" = "True" ]]; then
         # This assumes you want a simple configuration, and will overwrite
         # Q_SRV_EXTRA_OPTS if set in addition to ENABLE_TENANT_TUNNELS.
-        Q_SRV_EXTRA_OPTS=(tenant_network_types=gre)
+        Q_SRV_EXTRA_OPTS+=(tenant_network_types=gre)
         Q_ML2_PLUGIN_GRE_TYPE_OPTIONS=(tunnel_id_ranges=$TENANT_TUNNEL_RANGES)
     elif [[ "$ENABLE_TENANT_VLANS" = "True" ]]; then
-        Q_SRV_EXTRA_OPTS=(tenant_network_types=vlan)
+        Q_SRV_EXTRA_OPTS+=(tenant_network_types=vlan)
     else
         echo "WARNING - The ml2 plugin is using local tenant networks, with no connectivity between hosts."
     fi