diff --git a/src/server/distrend.c b/src/server/distrend.c
--- a/src/server/distrend.c
+++ b/src/server/distrend.c
@@ -495,6 +495,7 @@ int interactiveTest(int test, struct gen
        test = 0;
        break;
      default:
+       fprintf(stderr, "Invalid input, please try again.\n");
        break;
      }
    }