diff --git a/src/barebox-state.c b/src/barebox-state.c
index 23b7e97..e0902ab 100644
--- a/src/barebox-state.c
+++ b/src/barebox-state.c
@@ -475,6 +475,12 @@
 			++nr_states;
 			break;
 		}
+		case ':':
+		case '?':
+		default:
+			exit(1);
+			break;
+
 		}
 	}