diff --git a/usr/bin/lxchelper b/usr/bin/lxchelper
index 3afc20e..c64e9ba 100755
--- a/usr/bin/lxchelper
+++ b/usr/bin/lxchelper
@@ -65,4 +65,8 @@ parser_extract.add_argument('container', help='Container name')
 parser_extract.add_argument('source', help='Source file or directory within the container')
 parser_extract.add_argument('destination', help='Destination file or directory on the host')
 
-main(parser.parse_args())
+args = parser.parse_args()
+if hasattr(args, 'action'):
+    main(args)
+else:
+    parser.print_usage()
diff --git a/usr/bin/lxcmgr b/usr/bin/lxcmgr
index 8f3827f..89e1582 100755
--- a/usr/bin/lxcmgr
+++ b/usr/bin/lxcmgr
@@ -105,6 +105,7 @@ parser = argparse.ArgumentParser(description='LXC container and package manager'
 subparsers = parser.add_subparsers()
 
 parser_list = subparsers.add_parser('list')
+parser_list.set_defaults(action='list-installed')
 subparsers_list = parser_list.add_subparsers()
 parser_list_installed = subparsers_list.add_parser('installed')
 parser_list_installed.set_defaults(action='list-installed')
@@ -125,4 +126,8 @@ parser_uninstall = subparsers.add_parser('uninstall')
 parser_uninstall.set_defaults(action='uninstall')
 parser_uninstall.add_argument('app', help='Application to uninstall')
 
-main(parser.parse_args())
+args = parser.parse_args()
+if hasattr(args, 'action'):
+    main(args)
+else:
+    parser.print_usage()
diff --git a/usr/bin/vmmgr b/usr/bin/vmmgr
index edf411f..6263790 100755
--- a/usr/bin/vmmgr
+++ b/usr/bin/vmmgr
@@ -6,6 +6,24 @@ import argparse
 from vmmgr.config import Config
 from vmmgr.vmmgr import VMMgr
 
+def main(args):
+    vmmgr = VMMgr(Config())
+    if args.action == 'register-app':
+        # Used by package install.sh script
+        vmmgr.register_app(args.app, args.host, args.login, args.password)
+    elif args.action == 'unregister-app':
+        # Used by package uninstall.sh script
+        vmmgr.unregister_app(args.app)
+    elif args.action == 'rebuild-issue':
+        # Used by inittab on VM startup
+        vmmgr.rebuild_issue()
+    elif args.action == 'register-proxy':
+        # Used in init scripts on application startup
+        vmmgr.register_proxy(args.app)
+    elif args.action == 'unregister-proxy':
+        # Used in init scripts on application stop
+        vmmgr.unregister_proxy(args.app)
+
 parser = argparse.ArgumentParser(description='VM application manager')
 subparsers = parser.add_subparsers()
 
@@ -32,19 +50,7 @@ parser_unregister_proxy.set_defaults(action='unregister-proxy')
 parser_unregister_proxy.add_argument('app', help='Application name')
 
 args = parser.parse_args()
-vmmgr = VMMgr(Config())
-if args.action == 'register-app':
-    # Used by package install.sh script
-    vmmgr.register_app(args.app, args.host, args.login, args.password)
-elif args.action == 'unregister-app':
-    # Used by package uninstall.sh script
-    vmmgr.unregister_app(args.app)
-elif args.action == 'rebuild-issue':
-    # Used by inittab on VM startup
-    vmmgr.rebuild_issue()
-elif args.action == 'register-proxy':
-    # Used in init scripts on application startup
-    vmmgr.register_proxy(args.app)
-elif args.action == 'unregister-proxy':
-    # Used in init scripts on application stop
-    vmmgr.unregister_proxy(args.app)
+if hasattr(args, 'action'):
+    main(args)
+else:
+    parser.print_usage()