diff --git a/test262/config.py b/test262/config.py
index 9bcf2ac9f083c037caa659ddc3699f6bb1bbd873..7e3cb5068c6e460d079fc7504a28b5b188d6eb3d 100755
--- a/test262/config.py
+++ b/test262/config.py
@@ -107,4 +107,4 @@ ARK_ARCH_LIST = [
 DEFAULT_ARK_ARCH = ARK_ARCH_LIST[0]
 DEFAULT_OPT_LEVEL = 2
 DEFAULT_ES2ABC_THREAD_COUNT = 0
-DEFAULT_MERGE_ABC_MODE = 0
+DEFAULT_MERGE_ABC_MODE = 1