diff --git a/TODO b/TODO
index a6cab46..43e5fe2 100644
--- a/TODO
+++ b/TODO
@@ -2,7 +2,6 @@ TODO:
 
 * Duplication of first maintainer when editing to add a second?
 * Try to re-use existing recipe record with same PN instead of deleting and re-creating (if within same layer)
-* Update script should error out with extra unused parameters - too easy to forget to use -l with layer list
 * meta-arago-extras is preferred over meta-networking e.g. for crda; probably need an explicit field for priority order
 * Update script does not report which layer failed with -q when fetch fails
 * Document macros for URL fields
diff --git a/layerindex/update.py b/layerindex/update.py
index 1582d80..c32d8cc 100755
--- a/layerindex/update.py
+++ b/layerindex/update.py
@@ -179,6 +179,10 @@ def main():
 
 
     options, args = parser.parse_args(sys.argv)
+    if len(args) > 1:
+        logger.error('unexpected argument "%s"' % args[1])
+        parser.print_help()
+        sys.exit(1)
 
     # Get access to our Django model
     newpath = os.path.abspath(os.path.dirname(os.path.abspath(sys.argv[0])) + '/..')