diff --git a/openbsc/src/gprs/gtphub_main.c b/openbsc/src/gprs/gtphub_main.c
index 0a7d383..f56c446 100644
--- a/openbsc/src/gprs/gtphub_main.c
+++ b/openbsc/src/gprs/gtphub_main.c
@@ -276,7 +276,8 @@
 			ccfg->restart_counter_file = optarg;
 			break;
 		default:
-			/* ignore */
+			LOGP(DGTPHUB, LOGL_FATAL, "Invalid command line argument, abort.\n");
+			exit(1);
 			break;
 		}
 	}