diff --git a/t/helper/test-reftable.c b/t/helper/test-reftable.c
index 26b03d7b78..1f0a28cbb6 100644
--- a/t/helper/test-reftable.c
+++ b/t/helper/test-reftable.c
@@ -3,15 +3,16 @@
 
 int cmd__reftable(int argc, const char **argv)
 {
+	/* test from simple to complex. */
 	basics_test_main(argc, argv);
-	block_test_main(argc, argv);
-	merged_test_main(argc, argv);
-	pq_test_main(argc, argv);
 	record_test_main(argc, argv);
-	refname_test_main(argc, argv);
-	readwrite_test_main(argc, argv);
-	stack_test_main(argc, argv);
+	block_test_main(argc, argv);
 	tree_test_main(argc, argv);
+	pq_test_main(argc, argv);
+	readwrite_test_main(argc, argv);
+	merged_test_main(argc, argv);
+	stack_test_main(argc, argv);
+	refname_test_main(argc, argv);
 	return 0;
 }