diff --git a/toplev.py b/toplev.py
index 7cd82bf4..203a784a 100755
--- a/toplev.py
+++ b/toplev.py
@@ -4493,7 +4493,7 @@ def main(args, rest, feat, env, cpu):
     check_exclusive(args, kernel_version)
     runner_list = init_runner_list(kernel_version)
     global KEEP_UNREF
-    if len(runner_list) > 1 and args.no_multiplex:
+    if len(runner_list) > 1 and isinstance(KEEP_UNREF, bool):
         KEEP_UNREF = True # for now -- dummy can get assigned to wrong runner
     handle_more_options(args)
     version = runner_emaps(setup_pe(), runner_list)