diff --git a/test/plugin/test_out_forward.rb b/test/plugin/test_out_forward.rb
index 306d9d8234..c2442b631a 100644
--- a/test/plugin/test_out_forward.rb
+++ b/test/plugin/test_out_forward.rb
@@ -611,7 +611,6 @@ def try_write(chunk)
 
     @d = d = create_driver(config + %[
       require_ack_response true
-      ack_response_timeout 1s
       <buffer tag>
         flush_mode immediate
         retry_type periodic
@@ -659,7 +658,6 @@ def try_write(chunk)
 
     @d = d = create_driver(config + %[
       require_ack_response true
-      ack_response_timeout 10s
       <buffer tag>
         flush_mode immediate
         retry_type periodic