diff --git a/ec2/spark_ec2.py b/ec2/spark_ec2.py
index 9f2daad2b632333b9dc288493d5ec52d908531db..7affe6fffc9e1969f45fe88e825c6cd0772f1eca 100755
--- a/ec2/spark_ec2.py
+++ b/ec2/spark_ec2.py
@@ -103,7 +103,7 @@ def parse_args():
     parser.print_help()
     sys.exit(1)
   (action, cluster_name) = args
-  if opts.identity_file == None and action in ['launch', 'login']:
+  if opts.identity_file == None and action in ['launch', 'login', 'start']:
     print >> stderr, ("ERROR: The -i or --identity-file argument is " +
                       "required for " + action)
     sys.exit(1)