diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index e471d7f53c..ce54828fbb 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -2987,8 +2987,8 @@ static struct config_int ConfigureNamesInt[] =
 
 	{
 		{"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
-			gettext_noop("Sets the planner's assumption about the size of the data cache."),
-			gettext_noop("That is, the size of the cache used for PostgreSQL data files. "
+			gettext_noop("Sets the planner's assumption about the total size of the data caches."),
+			gettext_noop("That is, the total size of the caches (kernel cache and shared buffers) used for PostgreSQL data files. "
 						 "This is measured in disk pages, which are normally 8 kB each."),
 			GUC_UNIT_BLOCKS,
 		},