diff --git a/controllerconfig/controllerconfig/upgrade-scripts/81-create-required-platform-certs.py b/controllerconfig/controllerconfig/upgrade-scripts/81-create-required-platform-certs.py
index 662121f37a..d42b607b67 100644
--- a/controllerconfig/controllerconfig/upgrade-scripts/81-create-required-platform-certs.py
+++ b/controllerconfig/controllerconfig/upgrade-scripts/81-create-required-platform-certs.py
@@ -57,6 +57,10 @@ def main():
             to_release = sys.argv[arg]
         elif arg == 3:
             action = sys.argv[arg]
+        elif arg == 4:
+            # optional port parameter for USM upgrade
+            # port = sys.argv[arg]
+            pass
         else:
             print("Invalid option %s." % sys.argv[arg])
             return 1