diff --git a/main.py b/main.py
index 889fc21..2ab79b5 100755
--- a/main.py
+++ b/main.py
@@ -197,6 +197,7 @@
     cmd_event = cmd.event_log.Add(name, event_log.TASK_COMMAND, start)
     cmd.event_log.SetParent(cmd_event)
     try:
+      cmd.ValidateOptions(copts, cargs)
       result = cmd.Execute(copts, cargs)
     except (DownloadError, ManifestInvalidRevisionError,
         NoManifestException) as e: