diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java
index 76f164f..fe5f483 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java
@@ -438,6 +438,10 @@
 
     @Override
     public void deleteExternalPeerRouter(ExternalGateway externalGateway) {
+        if (externalGateway == null) {
+            return;
+        }
+
         IpAddress targetIp = getExternalPeerRouterIp(externalGateway);
         if (targetIp == null) {
             return;
@@ -555,6 +559,9 @@
     }
 
     private IpAddress getExternalPeerRouterIp(ExternalGateway externalGateway) {
+        if (externalGateway == null) {
+            return null;
+        }
         Optional<Subnet> externalSubnet = subnets(externalGateway.getNetworkId())
                 .stream()
                 .findFirst();