diff --git a/libunwind/test/lit.cfg b/libunwind/test/lit.cfg
--- a/libunwind/test/lit.cfg
+++ b/libunwind/test/lit.cfg
@@ -67,9 +67,10 @@
 configuration = config_module.Configuration(lit_config, config)
 configuration.configure()
 configuration.print_config_info()
-if lit_config.params.get('use_new_format', False):
-    lit_config.note("Using the experimental libc++ testing format")
+if lit_config.params.get('use_old_format', False):
+    lit_config.note("Using the old libc++ testing format")
+    config.test_format = configuration.get_test_format()
+else:
+    lit_config.note("Using the new libc++ testing format")
     import libcxx.test.newformat
     config.test_format = libcxx.test.newformat.CxxStandardLibraryTest()
-else:
-    config.test_format = configuration.get_test_format()