diff --git a/iocBoot/iocxxx/examples/serial_soft.cmd b/iocBoot/iocxxx/examples/serial_soft.cmd
index aa6bed1a8d250781fd83c42024a8867df1720263..1bad3ec3b0ae71c0cdc5e0831b8ad4f018838c1b 100644
--- a/iocBoot/iocxxx/examples/serial_soft.cmd
+++ b/iocBoot/iocxxx/examples/serial_soft.cmd
@@ -20,6 +20,6 @@ asynOctetConnect("serial2", "serial2")
 #asynOctetConnect("serial4", "serial4")
 
 # Load asynRecord and deviceCmdReply records for ports
-iocshLoad("$(IP)/iocsh/loadSerialComm.iocsh", "P=$(PREFIX), PORT0=serial1, PORT1=serial2, PORT2=serial3, PORT4=serial4")
+iocshLoad("$(IP)/iocsh/loadSerialComm.iocsh", "P=$(PREFIX), PORT0=serial1, PORT1=serial2, PORT2=serial3, PORT3=serial4")
 
 # END serial.cmd --------------------------------------------------------------