diff --git a/ssh-rand-helper.c b/ssh-rand-helper.c
index 8b1c4b4..0fcda7f 100644
--- a/ssh-rand-helper.c
+++ b/ssh-rand-helper.c
@@ -853,11 +853,17 @@
 		default:
 			error("Invalid commandline option");
 			usage();
+			exit(1);
 		}
 	}
-
 	log_init(argv[0], ll, SYSLOG_FACILITY_USER, 1);
 
+	if (argc != optind) {
+		error("Unexpected commandline arguments.");
+		usage();
+		exit(1);
+	}
+
 #ifdef USE_SEED_FILES
 	prng_read_seedfile();
 #endif