diff --git a/scrapy/settings/default_settings.py b/scrapy/settings/default_settings.py
index 260ec1701..9660e0bcd 100644
--- a/scrapy/settings/default_settings.py
+++ b/scrapy/settings/default_settings.py
@@ -240,6 +240,10 @@ METAREFRESH_MAXDELAY = 100
 
 NEWSPIDER_MODULE = ""
 
+PERIODIC_LOG_DELTA = None
+PERIODIC_LOG_STATS = None
+PERIODIC_LOG_TIMING_ENABLED = None
+
 RANDOMIZE_DOWNLOAD_DELAY = True
 
 REACTOR_THREADPOOL_MAXSIZE = 10