diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackFlowTraceCommand.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackFlowTraceCommand.java
index 69ba0dc..bbaaaff 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackFlowTraceCommand.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackFlowTraceCommand.java
@@ -67,7 +67,7 @@
         if (srcNode == null || srcNode.sshAuthInfo() == null) {
             log.error("Openstack node {} is null or has no SSH authentication information.\n" +
                             " Please refers to the sample network-cfg.json in OpenstackNode app to push" +
-                            "SSH authentication information", srcNode.hostname());
+                            "SSH authentication information", srcNode == null ? "" : srcNode.hostname());
 
             return;
         }