diff --git a/src/hnbgw.c b/src/hnbgw.c
index 9dc67a2..0db04af 100644
--- a/src/hnbgw.c
+++ b/src/hnbgw.c
@@ -455,6 +455,11 @@
 			break;
 		}
 	}
+
+	if (argc > optind) {
+		fprintf(stderr, "Unsupported positional arguments on command line\n");
+		exit(2);
+	}
 }
 
 CTRL_CMD_DEFINE_RO(hnb_info, "info");