diff --git a/degesch.c b/degesch.c
index a06ef24..58fd303 100644
--- a/degesch.c
+++ b/degesch.c
@@ -13452,6 +13452,11 @@ main (int argc, char *argv[])
 		opt_handler_usage (&oh, stderr);
 		exit (EXIT_FAILURE);
 	}
+	if (optind != argc)
+	{
+		opt_handler_usage (&oh, stderr);
+		exit (EXIT_FAILURE);
+	}
 	opt_handler_free (&oh);
 
 	// We only need to convert to and from the terminal encoding