diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index d6b57e5a2e1d..4ba5bf13a010 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -457,7 +457,8 @@ int main(int argc, char **argv)
 
 	nr_pages_per_cpu = bytes / page_size / nr_parallel;
 	if (!nr_pages_per_cpu) {
-		_err("invalid MiB");
+		_err("pages_per_cpu = 0, cannot test (%lu / %lu / %lu)",
+			bytes, page_size, nr_parallel);
 		usage();
 	}