diff --git a/src/event/ngx_event.c b/src/event/ngx_event.c
index 47f85ca09b..132708e270 100644
--- a/src/event/ngx_event.c
+++ b/src/event/ngx_event.c
@@ -826,7 +826,7 @@ ngx_event_process_init(ngx_cycle_t *cycle)
 #if (NGX_HAVE_REUSEPORT)
                 && !ls[i].reuseport
 #endif
-               ) 
+               )
             {
                 continue;
             }
@@ -1312,7 +1312,7 @@ ngx_event_core_init_conf(ngx_cycle_t *cycle, void *conf)
 
     ngx_conf_init_value(ecf->multi_accept, 0);
     ngx_conf_init_value(ecf->accept_mutex, 1);
-    ngx_conf_init_msec_value(ecf->accept_mutex_delay, 100);
+    ngx_conf_init_msec_value(ecf->accept_mutex_delay, 500);
 
 #if (NGX_HAVE_REUSEPORT)
     ngx_conf_init_value(ecf->reuse_port, 0);